Influence of using different proportions of cow and goat milk on the chemical, textural and sensory properties of Chanco–style cheese with equal composition

LWT - Food Science and Technology 112 (2019) 108226

Contents lists available at ScienceDirect

LWT - Food Science and Technology journal homepage: www.elsevier.com/locate/lwt

Influence of using different proportions of cow and goat milk on the chemical, textural and sensory properties of Chanco–style cheese with equal composition

T

Stefanie Vyhmeistera, Carolina Geldsetzer-Mendozaa, Marcela Medel-Marabolíb, Angélica Fellenberga, Einar Vargas-Bello-Péreza,c, Rodrigo A. Ibáñeza,∗ a

Departamento de Ciencias Animales, Facultad de Agronomía e Ingeniería Forestal, Pontificia Universidad Católica de Chile, Avenida Vicuña Mackenna, 4860, Macul, Santiago, Chile Departamento de Agroindustria y Enología, Facultad de Ciencias Agronómicas, Universidad de Chile, Avenida Santa Rosa, 11315, La Pintana, Santiago, Chile c Department of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Grønnegårdsvej 3, DK-1870, Frederiksberg C, Denmark b

A R T I C LE I N FO

A B S T R A C T

Keywords: Chanco cheese Cow milk Goat milk Cheese proteolysis Cheese texture

The manufacture of traditional cheese varieties by mixing different proportions of cow and goat milk has become a common practice to obtain products with different appearance, texture and flavor. This study aimed to evaluate the effect of increasing the proportion of goat milk in the chemical, textural and sensory properties of Chanco-style cheese, a traditional variety from Chile and produced with pasteurized cow milk. A standardized cheese manufacture process was performed based on milk composition and differing in the proportions of cow and goat milk: 100% cow and 0% goat (100C), 67% cow and 33% goat (67C), 33% cow and 67% goat (33C), and 0% cow and 100% goat (0C). Similar composition, pH and melting were observed among treatments, but main differences were found in degradation of αs1-CN and peptide profile, levels of C6:0, C8:0, C10:0, C14:0 and C14:1 cis-9 fatty acids, fracture strain and whiteness index. Sensory analysis indicated that increasing proportions of goat milk led to cheeses with higher scores in whiteness and goat flavors. These results suggest that increasing proportions of goat milk in the manufacture of Chanco-style cheese could be a good alternative for consumers that are constantly searching for products with different properties.

1. Introduction Chanco cheese is a variety produced from pasteurized cow milk which is obtained by enzymatic coagulation, acid development by action of starter lactic acid bacteria, curd washing step to control development of excessive acidity, a curd cooking step at 38 °C and a gentle pressing. It is usually ripened for short periods of time ranging from 2 to 6 weeks at temperatures from 8 to 14 °C, leading to a semi-matured product with a semi-soft and buttery consistency, with abundant mechanical eyeholes of irregular shapes evenly distributed in the mass of the cheese (INN-Chile, 1999; Oliveira & Brito, 2006). Chanco cheese is one of the most important cheeses consumed in Chile (SERNAC-Chile, 2015). In recent years, the manufacture of traditional cheese varieties using a mixture of cow and goat milk has gained popularity in the dairy

industry, since consumers are willing to purchase and taste products with diverse appearance, flavor and texture development (Sheehan, Patel, Drake, & McSweeney, 2009). However, adulteration of goat milk by mixing it with varying proportions of cow milk into goat milk is considered as fraud, since commercial value of goat milk and its respective dairy products is higher than in cow (Rodrigues et al., 2012). Goat milk is similar to cow milk in basic composition; however certain differences in goat milk such as lack of β-carotene, higher levels of βcasein (CN), lower levels of αs1-CN and higher proportion of shortmedium fatty acids when contrast to cow milk, may impact the chemical, physical and sensory properties of cheese (Park, Juárez, Ramos, & Haenlein, 2007). In this context, several studies have evaluated the chemical, rheological and sensory properties of cheeses made with varying proportions of cow and goat milk. Ramírez-López and VélezRuiz (2018) made fresh cheese using different proportions of cow:goat

∗ Corresponding author. Departamento de Ciencias Animales, Facultad de Agronomía e Ingeniería Forestal, Pontificia Universidad Católica de Chile, Avda. Vicuña Mackenna, 4860, Macul, Santiago, Chile. E-mail address: [email protected] (R.A. Ibáñez).

https://doi.org/10.1016/j.lwt.2019.05.124 Received 18 January 2019; Received in revised form 8 May 2019; Accepted 29 May 2019 Available online 30 May 2019 0023-6438/ © 2019 Elsevier Ltd. All rights reserved.

LWT - Food Science and Technology 112 (2019) 108226

S. Vyhmeister, et al.

gently stirred for 10 min, followed by partial drain of whey (30% of total volume) and replaced with potable water at 31 °C, followed a cooking step from 31 to 38 °C at a heating rate of 1 °C every 3 min and maintained at that temperature until the pH decreased to 6.2, after which the whey was completely drained from vats. The curds were then maintained at 35 °C until the pH decreased to 5.5. The curd was milled, salted with sodium chloride at a level of 25 g/kg curd and equilibrated for additional 20 min. The salted curd was transferred to 1 kg cylindrical molds and pressed during 14 h at a pressure of 150 kPa. Experimental cheeses were vacuum sealed and ripened for 42 d at a temperature of 12 °C.

milk (90:10, 80:20, 70:30, 60:40) to evaluate the effect on the physicochemical, textural, rheological, and sensory properties over 15 d of ripening. Sant’Ana et al. (2013) also studied fresh cheese made from cow, goat milk and their mixtures (1:1) during a ripening of 21 d to evaluate the chemical and sensory properties. Imm et al. (2003) compared the textural and functional properties (i.e., melting and formation of free oil) of pasta filata cheeses made from goat and cow milks. Niro et al. (2014) analyzed the physicochemical, microbiological and sensorial properties of pasta filata cheeses manufactured with cow milk and a mixture of cow and goat milk (65:35). Queiroga et al. (2013), studied the nutritional, textural and sensory characteristics of semihard cheeses made from cow milk, goat milk and their mixtures (1:1) during 28 d ripening. Sheehan et al. (2009) studied the effect of replacing the proportion of cow milk (0, 25, 50, 75 and 100%) on the composition, lipolysis, volatile compounds and sensory properties of semi-hard goat cheeses ripened for 150 d. In general, these authors found that main differences in cheeses with higher levels of goat milk were associated with a whiter appearance and goat flavors. However, differences in rennet coagulation properties of milks (i.e., lower rennet coagulation time and weaker rennet strength in goat milk when compared to cow milk due to differences in composition of individual CN; Park et al., 2007) may lead to a great variation in gross composition of cheeses (Niro et al., 2014; Queiroga et al., 2013; Ramírez-López & Vélez-Ruiz, 2018; Sheehan et al., 2009) and hence affecting other properties, such as proteolysis, acid development, flavor, texture and melting properties. To the extent of our knowledge, there are no studies showing how the composition, quality and appearance, especially shape and size of mechanical eyeholes of Chanco cheese is affected by using varying levels of cow and goat milk. Therefore, the aim of the present study was to evaluate the effect of increasing the proportion of goat milk in the chemical, textural and sensory properties of Chanco cheeses with similar composition during a ripening period of 42 d.

2.3. Cheese composition, pH and proteolysis The composition of Chanco-style cheeses were determined after 14 d of ripening for moisture by the oven-drying method (AOAC, 2016), fat by Gerber method (INN-Chile, 1998), total protein (%N × 6.38) by Kjeldahl method (AOAC, 2016), ash by gravimetric method (AOAC, 2016) and salt by potentiometric method (Johnson & Olson, 1985). The cheese pH was measured at 1, 14, 28 and 42 d of ripening by inserting a spear tip pH probe (AD1030, Adwa Instruments Inc., Szeged, Hungary) into a cheese block previously equilibrated at 20 °C for 45 min. The content of residual lactose and lactic acid in cheeses were measured by HPLC at 1, 14, 28 and 42 d of ripening (Zeppa, Conterno, & Gerbi, 2001). The primary and secondary proteolysis of experimental cheeses were assessed by the water-soluble nitrogen (WSN) and 12% trichloroacetic soluble nitrogen (12% TCA-SN), respectively, at 1, 14, 28 and 42 d of ripening (Kuchroo & Fox, 1982). Degradation of αs1-and βCN was monitored by RP-HPLC. Briefly, 40 mg of cheese sample was diluted in 360 μL of deionized water and 1.6 mL of a denaturing buffer composed of 8 mol/L urea, 165 mmol/L Tris, 44 mmol/L sodium citrate and 0.33 mL/100 mL β-mercaptoethanol. Samples were completely solubilized by heating sample in a waterbath at 40 °C for 30 min and filtered through a 0.45 μm filter. Samples were analyzed according the methodology described by Ibáñez et al. (2019) using a Shimadzu Prominence system (Shimadzu Corporation, Tokyo, Japan). Degradation during ripening was expressed as percentage area of intact CNs from samples at 1 d of ripening. Finally, the peptide profile of < 3 kDa water soluble fraction of cheese samples was analyzed by RP-HPLC as described by Sousa and McSweeney (2001). The < 3 kDa water soluble extracts were obtained by ultrafiltration of water soluble extracts prepared for WSN analyses by using ultrafiltration centrifuge tubes (Amicon Ultrafiltration tubes with nominal molecular weight cut-off of 3 kDa, Merck®, Darmstadt, Germany). The obtained chromatograms were processed according to Piraino, Parente, and Mcsweeney (2004). All chromatographic analyses for proteins/peptides were performed using a Restek® Viva C4 column (5 μm spherical particle size, 300 Å pore size, 2.1 × 150 mm; Restek Corporation, Bellefonte, PA, USA).

2. Materials and methods 2.1. Milk Raw cow and goat milk were obtained from local dairy farms and standardized to a protein-to-fat ratio of 0.9:1.0. The composition of standardized cow milk was 11.75 ± 0.89 g/100 g total solids, 3.05 ± 0.10 g/100 g fat and 2.79 ± 0.17 g/100 g total protein; whereas the composition of standardized goat milk was 13.18 ± 1.28 g/100 g total solids, 5.20 ± 0.05 g/100 g fat and 4.67 ± 0.15 g/100 g total protein. 2.2. Cheese manufacture Three replicate cheesemaking trials, each consisting of four vats containing 20 kg cheesemilk, were undertaken over a 21 d period. Chanco-style cheese was manufactured in the pilot plant facilities from the faculty of Agronomy and Forestry, Pontifical Catholic University of Chile. Cow and goat milk were mixed to obtain four different proportions: 100% cow and 0% goat (100C), 67% cow and 33% goat (67C), 33% cow and 67% goat (33C), and 0% cow and 100% goat (0C). Each cheesemilk was batch pasteurized at 65 °C for 30 min and cooled to 31 °C. Starter culture (CHN22, Chr. Hansen, Milwaukee, WI, USA) was added at a level of 0.25 g/kg cheesemilk and left to ripen for 30 min under continuous stirring. Cheesemilks were supplemented with 0.26 g/kg cheesemilk of calcium chloride (77 g/100 g purity; Dilaco Ltda., Santiago, Chile) and equilibrated for 3 min. Chymosin [1000 International Milk Clotting Units (IMCU)/mL, Chy-Max® Ultra, Chr. Hansen, Milwaukee, WI, USA] was added to each vat at a level 0.1 mL/ kg cheesemilk. Addition levels of CaCl2 and chymosin were based on cheesemilks containing 3.2 g/100 g protein (Guinee, Mulholland, Kelly, & Callaghan, 2007). After 45–55 min, the curd was cut based on the firmness estimated by the cheesemaker and healed for 3 min, then

2.4. Cheese fatty acid profile Lipids from cheeses were extracted and analyzed using a gas chromatography-flame ionization detector (GC-FID; Shimadzu Scientific Instrument GC-2010, Columbia, MD, USA) with same conditions as reported by Vargas-Bello-Pérez et al. (2018). Fatty acid gas chromatography peaks were identified using a fatty acid methyl ester standard (FAME; Supelco 37 Component FAME mix, Bellefonte, Pennsylvania, USA) and reference standards for C18:1t11 and C18:1c9, t11 (Nu-ChekPrep. Inc., Elysian, MN, USA). 2.5. Cheese texture and melting Uniaxial compression test was performed on cheese samples using a TA-XT2 Texture Analyzer (Stable Micro Systems, Godalming, Surrey, UK) to determine fracture stress (σf) and fracture strain (i.e., Henky 2

LWT - Food Science and Technology 112 (2019) 108226

S. Vyhmeister, et al.

strain; εf; O'Callaghan & Guinee, 2004) at 14, 28 and 42 d of ripening. Cheese samples were cut into cylinders (16 mm diameter, 18 mm height) and stored overnight at 4 °C. Analysis was performed by compressing a cheese sample to 80% strain at a rate of 0.5 mm/s. At least five cheese cylinders were analyzed per treatment. Schreiber meltability test was used to measure the melting properties of cheeses (i.e., flowability) during ripening (Ibáñez, Waldron, & McSweeney, 2016a), by heating cheese discs at 232 °C for 5 min. Meltability was calculated as the percentage of increase in diameter of unmelted samples. All treatments were analyzed in triplicate at 14, 28 and 42 d of ripening.

2.8. Experimental design and statistical analysis Four treatments based on different proportions of cow and goat milk (100C, 67C, 33C and 0C) were used in three independent trials, based on a randomized 4 × 3 block design. Data were analyzed using ANOVA when differences between treatments were significant (P < 0.05). A split-plot design (Montgomery, 2013) was used to evaluate the effect of treatment, ripening time and their interactions on proteolysis, pH, lactic acid, texture, melting and color using a general linear model. The treatments means were analyzed by Tukey's multiple comparison test, when significant differences (P < 0.05) were found. All analyses were performed using Minitab Statistical Software 18 (Minitab Inc.®, State College, Pennsylvania, USA).

2.6. Color 3. Results

Color of experimental cheeses was performed with a CR-400 colorimeter® (Konika-Minolta Optics Inc., Osaka, Japan) at 1, 7, 14, 28 and 42 d of ripening, using the CIELAB color system, a D65 illuminant and a visual angle of 2°. Five random measurements were performed directly on a fresh cut of cheese at 20 °C (Ibáñez et al., 2016a). With color data, the whiteness index (WI = L* – 3 b*) was calculated as described by Marcone and Kakuda (1999).

3.1. Cheese composition, pH and proteolysis The composition of Chanco-style cheeses is shown in Table 2. Increasing proportion of goat milk resulted in cheeses with no significant differences (P > 0.05) in composition and pH values (Table 2). Levels of residual lactose were similar at 1 d of ripening and after 14 d of ripening, no lactose was detected in any treatment (Table 2). In contrast to residual lactose, levels of lactic acid exhibited a slight increase after 14 d of ripening and remained constant thereafter (Table 2). Despite all treatments exhibited similar pH values (P > 0.05), there was a significant increase during cheese ripening (P < 0.05). The primary and secondary proteolysis of experimental cheeses are shown in Table 2. Ripening time had a significant effect on levels of proteolysis (P < 0.05), exhibiting an increase of WSN/TN and 12% TCA-SN/TN for all treatments (Table 2). However, cheese treatment had no significant effect (P > 0.05) on levels of both primary and secondary proteolysis (Table 2). In contrast to these results, degradation of αs1-CN showed a significant interaction treatment × ripening

2.7. Sensory analysis The sensory properties of cheeses at 42 d of ripening was analyzed by Spectrum and quantitative sensory analysis (Meilgaard, Civille, & Carr, 1999). Cheese cubes (2 × 2 × 2 cm) at 12 °C were evaluated by 12 panelists (15 h training) using a numerical scale (0–15). Attributes described were whiteness, eyes, hardness, cohesiveness, particle size, sweet, salt, acid, bitter, milkfat, goat, cow, pungent and astringent as shown in Table 1.

Table 1 Definition of the attributes used by trained panelists to evaluate the sensory properties of Chanco-style cheeses at 12 °C using a combination of Spectrum and quantitative descriptive analysis. Attribute

Definition and evaluation procedure

References used, preparation instructions and anchor points (015)

Whiteness

Degree of white color developed in cheese sample.

Eyes

Amount of holes distributed in the cheese surface

Hardness

Force required to fracture cheese sample using molars.

Cohesiveness

Degree to which sample holds together in mass after chewing 7 times.

Particle size

Size of the particles in the mass after chewing 15 times.

Sweet Salt Acid Bitter Milkfat Goat Cow Pungent

Basic taste sensation elicited by sweet compounds. Basic taste sensation elicited by salt. Basic taste sensation elicited by acids. Basic taste sensation elicited by bitter compounds Aromatics and flavor associated with milk or fresh cream. Aromatics and flavor associated with goats. Aromatics and flavor associated with cow. Chemical feeling factor associated with high concentrations of irritants to the mucous membranes of the oral cavity Harsh, drying, puckering sensation on the surfaces of the mouth.

Cheddar-type processed cheese (orange color; Quillayes) = 0.0. Chanco cheese (intense yellow color; Las Parcelas de Valdivia) = 7.5. Fresco cheese (white color; Quillayes) = 15.0. No eyes = 0.0. Eyes distributed in ≤5% of cheese surface = 3.0. Eyes distributed in ≤25% of cheese surface = 6.0. Eyes distributed in ≤40% of cheese surface = 10.0. Eyes distributed in ≥60% of cheese surface = 13.0. Philadelphia full-fat cheese (Kraft Foods) = 0.5 Sureña sausage (Cecinas Llanquihue) = 5.0. Almond (Walmart) = 12.0 Carrot (Walmart) = 0.5 Crackelet Crackers (Costa) = 7.0 White bread (Ideal) = 14.0. Philadelphia full-fat cheese (Kraft Foods) = 0.5 Parmesan cheese (Colun) = 5.0. Provoletta cheese (Pahuilmo) = 10.0. None to pronounced. None to pronounced. None to pronounced. None to pronounced. None to pronounced. None to pronounced. None to pronounced. None to pronounced.

Astringent

None to pronounced.

Attributes were evaluated using Spectrum and quantitative descriptive analysis (Meilgaard et al., 1999). 3

LWT - Food Science and Technology 112 (2019) 108226

S. Vyhmeister, et al.

Table 2 Composition (14 d) and levels of residual lactose, lactic acid, pH and proteolysis during the ripening of Chanco-style cheese manufactured with 100% cow and 0% goat milk (100C), 67% cow and 33% goat milk (67C), 33% cow and 67% goat milk (33C), and 0% cow and 100% goat milk (0C). Treatment 2

Parameter

100C

Moisture (g/100 g) 48.16a Fat (g/100 g) 26.50a Protein (g/100 g 20.45a Salt (g/100 g) 1.70a MNFS (%) 65.53a FDM (%) 51.67a S/M (%) 3.48a Ash (g/100 g) 3.93ab Residual lactose (g/100 g) 1d 0.31a 14 d ND 28 d ND 42 d ND Lactic acid (g/100 g) 1d 1.45a,B 14 d 1.69a,A 28 d 1.71 a,A 42 d 1.79 a,A pH (−) 1d 5.28a,C 14 d 5.37a,BC 28 d 5.43a,AB 42 d 5.48a,A WSN/TN (%) 1d 4.49a,B 14 d 9.61b,AB 28 d 12.42a,A 42 d 15.23a,A 12% TCA SN/TN (%) 1d 0.55a,B 14 d 1.36 a,B 28 d 6.36 a,A 42 d 7.33 a,A

67C

33C

0C

SEM

47.61a 27.17a 20.35a 1.69a 65.36a 52.56a 3.41a 3.79b

48.23a 27.00a 19.76a 1.64a 66.07a 51.85a 3.55a 4.08ab

47.75a 27.00a 19.95a 1.66a 65.41a 51.12a 3.53a 4.45a

0.15 0.25 0.40 0.05 0.16 0.47 0.10 0.13

0.23a ND ND ND

0.21a ND ND ND

0.34a ND ND ND

0.03 -

1.75 1.96 2.05 2.06

a,B a,A a,A a,A

1.74 2.02 2.01 2.00

a,B a,A a,A a,A

1.46 1.72 1.73 1.74

a,B a,A a,A a,A

0.06 0.05 0.06 0.05

5.17a,B 5.30a,A 5.38a,A 5.40a,A

5.20a,C 5.33a,B 5.41a,AB 5.45a,A

5.28a,C 5.39a,B 5.52a,A 5.55a,A

0.02 0.02 0.02 0.02

6.16a,C 8.81b,BC 13.79a,AB 15.84a,A

6.19a,C 9.42b,BC 12.53a,AB 16.75a,A

8.20a,B 16.11a,A 17.49a,A 16.22a,A

0.87 0.94 0.75 0.44

0.58 2.03 6.95 7.86

a,B a,B a,A a,A

0.56 2.08 6.32 8.55

a,B a,B a,A a,A

0.36 1.77 7.98 8.93

a,B a,B a,A a,A

0.05 0.20 0.28 0.48

Fig. 1. Levels of intact αs1-CN (a) and β-CN (b) during the ripening of Chancostyle cheeses made from cheesemilks containing 100% cow milk, 0% goat milk (100C; ●); 67% cow milk, 33% goat milk (67C; ○); 33% cow milk, 67% goat milk (33C; ▼); and 0% cow milk, 100% goat milk (100C; Δ). Values represent mean and standard deviation of three replicate trials.

Data are means and standard error of three replicate trials. a,b,c Means within the same row not sharing a common superscript differ (P < 0.05). A,B,C Means within the same column (for a particular item) not sharing a common uppercase superscript differ (P < 0,05; comparing the effect of ripening at a single treatment). Abbreviations are: MNFS, moisture in the non-fat substance; FDM, fat content on a dry basis weight; S/M, salt in the moisture phase of the cheese; WSN/TN, water soluble-nitrogen as percentage of total nitrogen; 12% TCA SN/TN, 12% trichloroacetic acid soluble-nitrogen as percentage of total nitrogen.

chromatograms are shown in Fig. 3. Two components (PC1 and PC2) accounted for 76.3% of total variance. The PC1 separated samples among treatment, whereas PC2 by ripening time (Fig. 3a). Vectors loadings exhibited that 11 classes (i.e., peptides or groups of peptides) accounted for most of the differences (Fig. 3b). Classes 16 and 17 associated with cow, whereas classes 24 and 43 with goat. In addition, classes 22, 28 and 49 related to initial stages of cheese ripening (more hydrophobic), in contrast with classes 10, 19, 21 and 32 to later stages of cheese ripening (less hydrophobic).

(P < 0.05), where cheeses made with higher proportions of cow milk had higher degradation rate of intact αs1-CN during ripening (from 100 to 18% after 42 d), in contrast to those treatments made with higher proportions of goat milk (from 100 to 78% in 42 d; Fig. 1a). On the other hand, there were no significant differences (P > 0.05) in degradation of intact β-CN in experimental cheeses, but they all exhibited a significant reduction after 42 d of ripening (Fig. 1b; P < 0.05), in which levels decreased from 100% to 70-80%. The RP-HPLC peptide profile of the < 3 kDa water soluble extracts of experimental cheeses at 1, 14 and 42 d of ripening are shown in Fig. 2. Chromatograms exhibited qualitative and quantitative differences among treatments and ripening time. At 1 d of ripening (Fig. 2a) cheeses made with higher proportions of cow milk presented more characteristic peptide peaks near to 20 and 28 min of retention, whereas those treatments made with higher proportions of goat milk had peaks near to 25 min. Peptide profiles at 14 and 42 d of ripening (Fig. 2b and c) showed that characteristic peptide peaks from cow and goat treatments were more intense. The score and loading plots obtained from principal component analysis (PCA) of the peak height data of < 3 kDa cheese peptide

3.2. Fatty acid composition The fatty acid (FA) composition of cheeses are shown in Table 3. The amount of caproic (C6:0), caprylic (C8:0) and capric (C10:0) of short-chain FA were higher in cheeses made with higher proportions of goat milk, whereas medium-chain FA, such as myristic (C14:0) and myristolic (C14:1cis-9) were higher in cheeses made with higher proportions of cow milk. 3.3. Cheese texture, melting and whiteness index Chanco-style cheeses made with increased proportion of goat milk exhibited similar fracture stress (σf; P > 0.05; Fig. 4a) and reduced Henky strain (εf; P < 0.05; Fig. 4b) when compared to treatments with higher proportion of cow milk. During cheese ripening, the σf was significantly reduced (P < 0.05), whereas the εf remained constant in all treatments (P > 0.05). On the other hand, the Schreiber melting 4

LWT - Food Science and Technology 112 (2019) 108226

S. Vyhmeister, et al.

Fig. 3. Score (a) and loading (b) plots obtained by principal component analysis (PCA) from the < 3 kDa water soluble peptide profiles of experimental cheeses made from cheesemilks containing 100% cow milk, 0% goat milk (100C; ●); 67% cow milk, 33% goat milk (67C; ○); 33% cow milk, 67% goat milk (33C; ▼); and 0% cow milk, 100% goat milk (100C; Δ). Numbers indicate the position of classes in relation to the total.

those made with higher proportion of cow milk. Attributes of eyes, hardness, cohesiveness, particle size, sweetness, salt, acid, bitter, milkfat, cow notes, pungent and astringent were not significantly different among treatments (P > 0.05).

4. Discussion Fig. 2. Reverse-phase HPLC chromatograms of < 3 kDa soluble extracts of Chanco style cheeses made from cheesemilks containing 100% cow milk, 0% goat milk (100C); 67% cow milk, 33% goat milk (67C); 33% cow milk, 67% goat milk (33C); and 0% cow milk, 100% goat milk (100C) at 1 (a), 14 (b) and 42 d (c) of ripening.

The composition of Chanco-style cheeses manufactured with varying proportions of cow and goat milk was in accordance with Chilean legislation for Chanco cheese for moisture, fat, FDM and MNFS content (INN-Chile, 1999). In general, cheeses made with increased proportions of goat-to-cow milk tend to exhibit reduced moisture content in several varieties (Niro et al., 2014; Sant’Ana et al., 2013; Sheehan et al., 2009). However, similarities in composition of experimental cheeses found in our study could be related to standardized manufacturing procedures, which were based on the addition of calcium chloride and rennet in function of cheesemilk composition (Guinee et al., 2007), cutting the curd at similar firmness (as determined by the cheesemaker: 45 min for 100C and 55 min for 0C) and controlling curd temperature and pH at critical points during cheese manufacture. In general, the use of whey dilution is extensively used to reduce and control acid development in cheese (Shakeel-Ur-Rehman, Waldron, & Fox, 2004). This technique, along with acidification of the curd at pH values of ∼5.5 may have resulted in obtaining cheeses with similar levels of residual lactose at 1 d, followed its complete depletion at 14 d of ripening that leads to similar levels of lactic acid and pH among treatments. In contrast, an increase in pH values of all

test (Fig. 4c) showed that increasing proportions of goat milk in Chanco-style cheeses did not affect meltability (P > 0.05), but significantly increased throughout ripening for all treatments (P < 0.05). As expected, cheeses made with higher proportions of goat milk exhibited higher whiteness index (WI) than those treatments made with higher proportions of cow milk (P < 0.05; Fig. 4d). In addition, all treatments exhibited a progressive reduction of WI during the 42 d of ripening (P < 0.05). 3.4. Sensory analysis The scored attributes obtained from sensory analysis of Chancostyle cheeses at 42 d of ripening are shown in Table 4. As expected, increasing proportion of goat milk led to cheeses with increased perception in whiteness and goat notes (P < 0.05), when compared to 5

LWT - Food Science and Technology 112 (2019) 108226

S. Vyhmeister, et al.

could relate to similar composition, pH and probably plasmin activity. Quantitative and qualitative changes in the peptide profile of experimental cheeses during ripening (Fig. 2) are in agreement with an increase in primary and secondary proteolysis (Table 1) and also differences in degradation patterns of αs1-and β-CN, which is attributed to varying levels of individual CN between cow and goat milk (Park et al., 2007). Principal component analysis (Fig. 3) was also able to identify characteristic peptide classes from cow or goat milk at different timepoints, which is in agreement with Diezhandino, Fernández, González, McSweeney, and Fresno (2015) that found a higher proportion of hydrophobic peptide classes at initial stages of ripening and a higher proportion of hydrophilic peptide classes thereafter. As expected, the FA analysis clearly showed that cheeses made with goat milk presented higher levels of short chain FA, such as caproic (C6:0), caprylic (C8:0) and capric (C10:0) FAs when compared to cow milk, which agrees with the findings of Queiroga et al. (2013) in Coalho cheeses made with cow, goat milk and a 50:50 mixture. In contrast, higher levels of C14:0, C16:0 and C16:1 FAs, as found in cheeses with higher proportion of cow milk, are associated with increasing risk of cardiovascular diseases (Huth & Park, 2012). The σf is an indicator of the strength of the cheese matrix and the εf defines its degree of brittleness (O'Callaghan & Guinee, 2004). Similar fracture stress found in experimental cheeses could be attributed due to similar composition, pH values and primary proteolysis among treatments (Table 1), whilst a decrease of σf values during the ripening time of all experimental cheeses could be attributed due to a softening of the cheese matrix, which is mainly caused by solubilization of colloidal calcium phosphate and an increase in the extent of proteolysis (Lucey, Johnson, & Horne, 2003). In contrast, reduced εf values (i.e., increased brittleness) found in cheeses made with increased proportions of goat milk could be attributed due to natural differences in levels of individual proteins when compared to cow milk, such as reduced and increased proportions of αs1-and β-CN, respectively (Queiroga et al., 2013; Ramírez-López & Vélez-Ruiz, 2018). O’Mahony, McSweeney, and Lucey (2008) hypothesized that higher levels of β-CN in model cheeses would contribute to a higher number of aggregates in the matrix, leading to a more rigid and brittle structure. We believe a similar phenomenon may also occur in experimental cheeses made from higher levels of goat milk, in which the contribution of reduced levels of αs1CN in cheese texture is compensated by increased levels β-CN, but with increased brittleness. Similar melting of experimental cheeses (Fig. 4c) could also be associated with similar composition, pH and extent of proteolysis and also agrees with the findings of Imm et al. (2003) for Mozzarella cheeses made with goat or cow milk, whereas an increase of meltability during ripening is attributed to a softening of the cheese matrix, as previously indicated for texture. Increased WI of experimental cheeses made with increased levels of goat milk is attributed due to the lack of β-carotene (responsible of giving yellow notes to milk and dairy products, such as cheese and butter), when compared to cow milk (Park et al., 2007), whereas a reduction in WI values as ripening time progresses was associated with changes in the cheese matrix, such as increasing proteolysis and solubilization of colloidal calcium phosphate (which also increases pH) that directly reduce cheese whiteness, leading into a translucent appearance (Ibáñez, Waldron, & McSweeney, 2016b). Sensory analyses of experimental cheeses (Table 4) are in agreement with those obtained by instrumental and chemical analyses, such as increased whiteness perceived in treatments made with higher levels of goat milk (Fig. 4d), similar hardness among treatments (Fig. 4a) and increased goat scores in cheeses made with higher proportion of goat milk due to higher levels of C6:0, C8:0 and C:10 FAs, when compared to those made with cow milk (Table 3). The latter results are in agreement with Queiroga et al. (2013) who found that goat notes are highly associated with increased levels of short-chain FA. Other similarities, such as found in mechanicals eyeholes, could also be associated with similar composition and proteolysis extent among treatments. Wadhwani and

Table 3 Fatty acid profile of Chanco-style cheeses made from cheesemilks containing 100% cow milk, 0% goat milk (100C), 67% cow milk, 33% goat milk (67C), 33% cow milk, 67% goat milk (33C) and 0% cow milk, 100% goat milk (100C). Treatment Fatty acid (g 100 g fat)

−1

cheese

C4:0 C6:0 C8:0 C10:0 C11:0 C12:0 C13:0 C14:0 C14:1 cis-9 C15:0 C15:1 C16:0 C16:1 C17:0 C17:1 C18:0 C18:1 trans-10 C18:1 trans-11 C18:1 cis-9 C18:2 trans-9, trans-12 C18:2 cis-9, cis-12 C18:3 cis-6, cis-9, cis-12 C18:3 cis-9, cis-12, cis-15 C18:2 cis-9, trans-11 C20:0 C20:1n-9 C20:2 C20:3n-6 Ʃ Saturated fatty acids Ʃ monounsaturated fatty acids Ʃ polyunsaturated fatty acids

SEM

P value

100C

67C

33C

0C

3.48a 1.99c 1.08c 2.63d 0.17a 2.93a 0.10a 9.30a 0.54a 0.71a 0.13a 27.16a 0.91a 0.69a 0.36a 11.61a 0.57a 0.93a 28.77a 0.39a 0.44a 0.13a 0.29a 3.96a ND 0.24a 0.21a ND 61.85a 32.22a

3.26a 2.25cb 1.80b 5.48c 0.17a 3.10a 0.07a 8.27ab 0.32b 0.68a 0.16a 26.28a 0.55a 0.43a 0.38a 10.10a ND 1.43a 29.61a 0.40a 0.64a 0.18a 0.47a 2.77a 0.14a 0.37a 0.35a 0.23a 61.89a 32.45a

2.94a 2.51ab 2.41ab 7.66b 0.23a 3.30a 0.08a 7.03bc 0.21b 0.65a 0.22a 23.99a 0.43a 0.60a 0.44a 10.04a 0.30a 0.54a 29.73a 1.48a 0.52a 0.32a 0.61a 2.91a 0.02a 0.36a 0.16a 0.09a 61.43a 31.85a

2.68a 2.54a 2.75a 9.31a 0.29a 3.50a 0.10a 6.76c 0.17b 0.65a 0.23a 24.19a 0.61a 0.48a 0.73a 8.62a 0.36a 1.15a 28.75a 1.51a 0.52a 0.31a 0.47a 2.57a 0.06a 0.31a 0.12a 0.22a 61.85a 32.01a

0.13 0.10 0.20 0.78 0.03 0.15 0.01 0.35 0.05 0.02 0.03 0.59 0.07 0.11 0.08 0.78 0.11 0.17 0.63 0.36 0.06 0.04 0.08 0.47 0.04 0.05 0.06 0.04 0.92 0.81

0.114 0.041 < 0.001 < 0.001 0.364 0.096 0.848 0.002 < 0.001 0.196 0.492 0.191 0.067 0.888 0.355 0.574 0.456 0.413 0.951 0.428 0.796 0.163 0.358 0.787 0.627 0.813 0.740 0.074 0.999 0.997

5.94a

5.53a

6.70a

6.08a

0.29

0.637

Data are means and standard error of three replicate trials. a,b,c Means within the same row not sharing a common superscript differ (P < 0.05).

experimental treatments during cheese ripening is related to solubilization of colloidal calcium phosphate that combine with hydrogen ions (Hassan, Johnson, & Lucey, 2004). The primary proteolysis estimates the total fraction of peptides (Kuchroo & Fox, 1982), whereas the secondary proteolysis only relates to the fraction of small peptides (Rank, Grappin, & Olson, 1985) produced by contribution of milk protein hydrolysis by chymosin, and proteinases and peptidases from lactic acid bacteria (starter and nonstarter). Similarities in the primary (WSN/TN) and secondary proteolysis (12% TCA SN/TN) of experimental cheeses relates to similar composition and pH values, in contrast to other studies that found increased proteolysis in cheeses made with higher proportion of (i) goat milk due to high cheese pH values and probably increased plasmin activity (Sheehan et al., 2009) and (ii) cow milk probably caused by low cheese pH values and increased residual rennet activity (Imm et al., 2003). A decrease in levels of intact αs1-CN during ripening is related to the activity of residual chymosin. We believe that the majority of goat αs1-CN was depleted during cheese manufacture, since this protein is more susceptible to chymosin hydrolysis when compared to cow milk (Trujillo, Guamis, & Carretero, 1998), leading to a small proportion of goat αs1-CN to degrade during ripening, when contrast to those treatments containing higher proportions of cow milk (Fig. 1a). A similar observation was described by Imm et al. (2003) who found no bands of αs1-CN when analyzed the protein profile of Mozzarella-style cheese made with goat milk at 1 d of ripening by SDS-polyacrylamide gel electrophoresis. In contrast, similarities in degradation rate of β-CN 6

LWT - Food Science and Technology 112 (2019) 108226

S. Vyhmeister, et al.

Fig. 4. Changes in fracture stress (σf; a), fracture strain (εf; b), Schreiber melting (c) and whiteness index estimated by CIELAB color space (WI; d) during the ripening of experimental cheeses made with 100% cow milk, 0% goat milk (100C; ■); 67% cow milk, 33% goat milk (67C;//); 33% cow milk, 67% goat milk (33C; ); and 0% cow milk, 100% goat milk (100C; □). Values represent mean and standard deviation of three replicate trials.

with consumer liking in Chanco-style cheeses made with different proportions of cow and goat milk.

Table 4 Sensory properties of Chanco-style cheeses made from cheesemilks containing 100% cow milk, 0% goat milk (100C), 67% cow milk, 33% goat milk (67C), 33% cow milk, 67% goat milk (33C) and 0% cow milk, 100% goat milk (100C) using a combination of Spectrum and quantitative descriptive analysis.

5. Conclusions

Treatment Attribute Whiteness Eyes Hardness Cohesiveness Particle size Sweet Salt Acid Bitter Milkfat Goat Cow Pungent Astringent

100C c

7.4 3.1a 6.4a 7.8a 4.0a 0.8a 5.1a 2.5a 1.4a 4.8a 1.1b 5.9a 1.1a 2.2a

67C

33C

c

b

7.8 3.4a 4.9a 9.1a 3.3a 1.2a 5.6a 4.9a 2.7a 5.4a 1.3b 5.1a 1.9a 2.7a

9.7 4.2a 4.1a 9.1a 3.0a 0.9a 5.6a 3.6a 3.1a 4.1a 4.4a 3.4a 1.8a 2.8a

0C 11.3 3.2a 5.7a 8.0a 4.6a 1.2a 5.6a 4.2a 3.5a 3.7a 5.6a 3.3a 1.8a 2.7a

a

SEM

P value

0.25 0.44 1.00 1.03 0.32 0.15 0.34 0.96 0.41 0.77 0.58 0.68 0.43 0.38

< 0.001 0.385 0.446 0.705 0.360 0.183 0.658 0.432 0.053 0.488 0.003 0.090 0.516 0.667

The results of this study provide evidence that increasing proportions of goat milk in the manufacture of Chanco cheese leads to cheeses with similar composition, if manufacture protocols are based on milk composition. In contrast, cheeses made with increased proportion of goat milk had lower degradation rate of intact αs1-CN, higher levels of caproic, caprylic and capric FAs and lower of myristic and myristolic FAs, reduced fracture strain, higher WI, and increased sensory perception of whiteness and goat notes, when compared with cheeses made with higher proportions of cow milk. Understanding how different proportions of goat milk influence cheese proteolysis, fatty acid profile, texture, appearance and flavor will allow dairy industry in obtaining varying cheese appearance, texture and flavor to satisfy consumer's needs. Acknowledgment

Data are means and standard error of three replicate trials. a,b,c Means within the same row not sharing a common superscript differ (P < 0.05).

This study was supported by “Programa de Inserción Académica Dr. Rodrigo A. Ibáñez, Vicerrectoria Académica, Pontificia Universidad Católica de Chile”, “Programa Tecnológico de Ingredientes Funcionales y Aditivos Naturales Especializados (CORFO, Chile; IFAN 16PTECAI66648-P16)”, “Taller 3 Module, Facultad de Agronomía e Ingeniería Forestal, Pontificia Universidad Católica de Chile (AGL060-2, 2017)” and “Fondo Nacional de Desarrollo Científico y Tecnológico”, Chile

McMahon (2012) found that excessive whiteness development in lowfat Cheddar cheese whiten with titanium dioxide led to reduced acceptability when analyzed by consumers hedonic analysis, hence further analysis should be made to establish optimum levels of whiteness 7

LWT - Food Science and Technology 112 (2019) 108226

S. Vyhmeister, et al.

(FONDECYT 1170400).

O'Callaghan, D. J., & Guinee, T. P. (2004). Rheology and texture of cheese. In (3rd ed.). P. F. Fox, P. L. H. McSweeney, T. M. Cogan, & T. P. Guinee (Vol. Eds.), Cheese: Chemistry, physics and microbiology: 1, (pp. 511–540). London, United Kingdom: Chapman and Hall. O'Mahony, J. A., McSweeney, P. L. H., & Lucey, J. A. (2008). Observations on the rheological and functional properties of model cheeses made using milk protein concentrate solutions with different ratios of as- and b-casein. Milchwissenschaft, 63, 145–148. Park, Y. W., Juárez, M., Ramos, M., & Haenlein, G. F. W. (2007). Physico-chemical characteristics of goat and sheep milk. Small Ruminant Research, 68, 88–113. Piraino, P., Parente, E., & Mcsweeney, P. L. H. (2004). Processing of chromatographic data for chemometric analysis of peptide profiles from cheese extracts: A novel approach. Journal of Agricultural and Food Chemistry, 52, 6904–6911. Queiroga, R. C. R. E., Santos, B. M., Gomes, A. M. P., Monteiro, M. J., Teixeira, S. M., de Souza, E. L., et al. (2013). Nutritional, textural and sensory properties of Coalho cheese made of goats', cows' milk and their mixture. LWT- Food Science and Technology, 50, 538–544. Ramírez-López, C., & Vélez-Ruiz, J. F. (2018). Effect of goat and cow milk ratios on the physicochemical, rheological, and sensory properties of a fresh Panela cheese. Journal of Food Science, 83, 1862–1870. Rank, T. C., Grappin, R., & Olson, N. F. (1985). Secondary proteolysis of cheese during ripening: A review. Journal of Dairy Science, 68, 801–805. Rodrigues, N. P. A., Givisiez, P. E. N., Queiroga, R. C. R. E., Azevedo, P. S., Gebreyes, W. A., & Oliveira, C. J. B. (2012). Milk adulteration: Detection of bovine milk in bulk goat milk produced by smallholders in northeastern Brazil by a duplex PCR assay. Journal of Dairy Science, 95, 2749–2752. Sant'Ana, A. M. S., Bezerril, F. F., Madruga, M. S., Batista, A. S. M., Magnani, M., Souza, E. L., et al. (2013). Nutritional and sensory characteristics of Minas fresh cheese made with goat milk, cow milk, or a mixture of both. Journal of Dairy Science, 96, 7442–7453. SERNAC-Chile (2015). Determinación de la composición nutricional en quesos Gouda, Mantecoso y Chanco y su contenido de sodio. https://www.sernac,cl/portal/607/ articles-4472_archivo_01.pdf/, Accessed date: 30 November 2018. Shakeel-Ur-Rehman, Waldron, D., & Fox, P. F. (2004). Effect of modifying lactose concentration in cheese curd on proteolysis and in quality of Cheddar cheese. International Dairy Journal, 14, 591–597. Sheehan, J. J., Patel, A. D., Drake, M. A., & McSweeney, P. L. H. (2009). Effect of partial or total substitution of bovine for caprine milk on the compositional, volatile, nonvolatile and sensory characteristics of semi-hard cheeses. International Dairy Journal, 19, 498–509. Sousa, M. J., & McSweeney, P. (2001). Studies on the ripening of Cooleeney, an Irish farmhouse Camembert-type cheese. Irish Journal of Agricultural & Food Research, 40, 83–95. Trujillo, A. J., Guamis, B., & Carretero, C. (1998). Hydrolysis of bovine and caprine caseins by rennet and plasmin in model systems. Journal of Agricultural and Food Chemistry, 46, 3066–3072. Vargas-Bello-Pérez, E., Gómez-Cortés, P., Geldsetzer-Mendoza, C., Morales, M. S., ToroMujica, P., Fellenberg, M. A., et al. (2018). Authentication of retail cheeses based on fatty acid composition and multivariate data analysis. International Dairy Journal, 85, 280–284. Wadhwani, R., & McMahon, D. J. (2012). Color of low-fat cheese influences flavor perception and consumer liking. Journal of Dairy Science, 95, 2336–2346. Zeppa, G., Conterno, L., & Gerbi, V. (2001). Determination of organic acids, sugars, diacetyl, and acetoin in cheese by high-performance liquid chromatography. Journal of Agricultural and Food Chemistry, 49, 2722–2726.

References AOAC (2016). Official methods of analysis (20th ed.). (Maryland, USA). Diezhandino, I., Fernández, D., González, L., McSweeney, P. L. H., & Fresno, J. M. (2015). Microbiological, physico-chemical and proteolytic changes in a Spanish blue cheese during ripening (Valdeón cheese). Food Chemistry, 168, 134–141.. Guinee, T. P., Mulholland, E. O., Kelly, J., & Callaghan, D. J. O. (2007). Effect of proteinto-fat ratio of milk on the composition, manufacturing efficiency, and yield of cheddar cheese. Journal of Dairy Science, 90, 110–123. Hassan, A., Johnson, M. E., & Lucey, J. A. (2004). Changes in the proportions of soluble and insoluble calcium during the ripening of Cheddar cheese. Journal of Dairy Science, 87, 854–862. Huth, P. J., & Park, K. M. (2012). Influence of dairy product and milk fat consumption on cardiovascular disease risk: A review of the evidence. Advances in Nutrition, 3, 266–285. Ibáñez, R. A., Vyhmeister, S., Muñoz, M. F., Brossard, N., Osorio, F., Salazar, F. N., et al. (2019). Influence of milk pH on the chemical, physical and sensory properties of a milk-based alcoholic beverage. Journal of Dairy Research. (in press) https://doi.org/ 10.1017/S0022029919000360. Ibáñez, R. A., Waldron, D. S., & McSweeney, P. L. H. (2016a). Effect of pectin on the composition, microbiology, texture, and functionality of reduced-fat Cheddar cheese. Dairy Science & Technology, 96, 297–316. Ibáñez, R. A., Waldron, D. S., & McSweeney, P. L. H. (2016b). Effect of fat content and temperature on the translucency of Cheddar cheese. International Dairy Journal, 54, 33–42. Imm, J. Y., Oh, E. J., Han, K. S., Oh, S., Park, Y. W., & Kim, S. H. (2003). Functionality and physico-chemical characteristics of bovine and caprine Mozzarella cheeses during refrigerated storage. Journal of Dairy Science, 86, 2790–2798. INN-Chile (1998). Normal Chilena Oficial NCh 1016/1 Of. 1998 Leche – determinacion del contenido de materia grasa – Método de Gerber – parte 1: Procedimiento. (Santiago, Chile). INN-Chile (1999). Norma chilena oficial NCh 2090. Of 1999. Productos lácteos – Queso Chanco – Requisitos. (Santiago, Chile). Johnson, M. E., & Olson, N. F. (1985). A comparison of available methods for determining salt levels in cheese. Journal of Dairy Science, 68, 1020–1024. Kuchroo, C., & Fox, P. F. (1982). Soluble nitrogen in Cheddar cheese: Comparison of extraction procedures. Milchwissenschaft, 37, 331–335. Lucey, J. A., Johnson, M. E., & Horne, D. S. (2003). Invited review: Perspectives on the basis of the rheology and texture properties of cheese. Journal of Dairy Science, 86, 2725–2743. Marcone, M. F., & Kakuda, Y. (1999). A comparative study of the functional properties of amaranth and soybean globulin isolates. Nahrung-Food, 43, 368–373. Meilgaard, M. M., Civille, G. V., & Carr, B. T. (1999). Selection and training of panel members. Sensory evaluation techniques (pp. 174–176). (3rd ed.). Boca Raton, FL: CRC Press. Montgomery, D. C. (2013). Design and analysis of experiments (8th ed.). Hoboken, NJ: John Wiley & Sons, Inc. Niro, S., Fratianni, A., Tremonte, P., Sorrentino, E., Tipaldi, L., Panfili, G., et al. (2014). Innovative Caciocavallo cheeses made from a mixture of cow milk with ewe or goat milk. Journal of Dairy Science, 97, 1296–1304. Oliveira, M. N., & Brito, C. (2006). Brined cheeses and analogues of Latin American origin. In A. Tamine (Ed.). Brined cheeses (pp. 211–248). Oxford, UK: Blackwell Publishing Ltd.

8