Production variations of nutritional composition of commercial meat products

Food Research International 43 (2010) 2378–2384

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Food Research International j o u r n a l h o m e p a g e : w w w. e l s ev i e r. c o m / l o c a t e / f o o d r e s

Production variations of nutritional composition of commercial meat products F. Jiménez-Colmenero a,⁎, T. Pintado a, S. Cofrades a, C. Ruiz-Capillas a, S. Bastida b a b

Instituto del Frío (CSIC), Ciudad Universitaria, 28040 Madrid, Spain Departamento de Nutrición, Facultad de Farmacia, Universidad Complutense de Madrid, 28040 Madrid, Spain

a r t i c l e

i n f o

Article history: Received 28 June 2010 Accepted 3 September 2010 Keywords: Meat products Nutrient composition Production variations Fatty acids

a b s t r a c t Changes in nutrient composition that habitually occur in commercial meat products in the course of production need to be considered for purposes of production systems control, consumer safety, nutritional information, labelling, official regulations or quality of food composition databases. This paper reports a study of production time variations in the nutritional composition of commercial meat products with different characteristics such as composition (protein and fat levels) and processing conditions (lean-only cuts, ground meat, fresh, cooked, brined, etc.). Proximate composition, fatty acid profile, cholesterol concentration, energy value and mineral content were evaluated. Over the year variability in nutrient composition were generally observed in meat products. The variability of composition (proximate analysis and fatty acid proportion) was greater in lean-only cut products as compared with ground meats. The relationship between fat and cholesterol contents of meat products presented correlation coefficients of 0.809 (P b 0.001) and 0.859 (P b 0.001) for the relationship between cholesterol and the sum of fat and protein contents. Several of the products considered are significant sources of Fe, Zn and K. Production variations in nutritional profiles observed in various meat products can affect the dietary assessment of some components, and also the product's nutritional labelling. © 2010 Elsevier Ltd. All rights reserved.

1. Introduction In the course of production, the nutritional composition of commercial meat products undergoes changes due to variations in the meat and non-meat ingredients and the processing conditions. Animal production practices (genetic and dietary strategies) play an important role in the nutritional quality of meat raw materials (Jiménez-Colmenero, Reig, & Toldrá, 2006). The composition (e.g. fat content and composition, mineral content) of pork is expected to reflect the variability of feeding management (time of feeding and type of feed), animal characteristics (breed, age, sex, weight, etc.) and environmental conditions, which depend on cultural practices, season and geographical factors. In the last few years there have been reports of changes in the nutritional composition of red meat as determined by various different factors (Higgs, 2000; Williamson, Foster, Stanner, & Buttriss, 2005; Jiménez-Colmenero et al., 2006). Meat products are generally made from various meat raw materials (from different origins and suppliers), which are combined at the formulation stage in obedience to criteria of composition, technological factors, sensory characteristics, legal regulations and also economics. The varying protein, fat, water or pigment contents of the various cuts of meat used mean that sometimes it is difficult to establish a high degree of control over the composition of the final product. Final products

⁎ Corresponding author. Tel.: + 34 91 549 23 00; fax: + 34 91 549 36 27. E-mail address: [email protected] (F. Jiménez-Colmenero). 0963-9969/$ – see front matter © 2010 Elsevier Ltd. All rights reserved. doi:10.1016/j.foodres.2010.09.009

characteristics are conditioned not only by quantitative aspects but also by technological properties of muscle protein. Protein functionality is responsible for determining the aptitude of meat proteins to yield product with specific characteristics (including composition) when subjected to certain processes (Nakai & Li-Chan, 1988). Many non-meat ingredients (from animal and plant sources) are used in the manufacture of products essentially for purposes of economy, functionality and composition. Characteristics and/or processing variations in these materials influence the processing and the physicochemical properties of meat products, and that affects their composition. Obviously various factors (including cost, production method, etc.) must be considered when choosing non-meat ingredients. Meat industry must sometimes choose its ingredient and formulate its products to suit the requirements (composition, cost, etc.) of certain customers (e.g. hypermarket chains) which are able to market them as “own brands”. In addition to the previous considerations, meat processing steps like grinding, cooking, smoking, brining, pickling, etc. have a considerable impact on processing (e.g. fat and water binding properties) and the characteristics of final meat products, including the composition. Changes in processing conditions can ensue from hitches in the production system or the need to adapt them to innovative technological developments (e.g. healthier meat products formulation). To address these considerations, meat processor can apply some strategies to control the quality of processed meat products in the presence of high variability of ingredients (Nakai & LiChan, 1988).

F. Jiménez-Colmenero et al. / Food Research International 43 (2010) 2378–2384

Production time variability in the nutrient composition of commercial meat products need to be considered for several reasons including production system quality control, consumer safety, nutritional information, labelling, official regulations or quality of food composition databases. This is especially important in that such changes may be great enough to produce a significant difference between the actual and the original target composition of the product. Regulation of food composition is essential for purposes of labelling, presentation and advertising of foods. Although consumer attitudes to meat are influenced by a number of factors (price, availability, culture, etc.), in recent years information about nutrient composition (labelling) has become increasingly important, especially for healthconscious consumers. The healthiness of a food product is not directly observable to the consumer so nutritional labelling is needed to make a healthy choice. However, production variations in nutrient composition mean that product won't meet consumer's nutritional expectation. This induces mistrust and may constitute financial fraud or even have negative effects on health. This will be the case if such changes affect compounds with implications for health (calories, saturated fatty acids, cholesterol, sodium, presence of allergens, etc.). Such changes are also extremely important with respect to food composition databases, which must reflect the real characteristics of the product. This is an essential aspect for the programming of food policies based on knowledge of energy and nutrient requirements and of the concentrations of these in foods. For a more realistic estimation of nutrient intake, we need to know the exact amount and final composition of the products consumed. There are numerous food composition tables and databases, including meat products, although with different nutrient values. These variations can be due to a variety of factors relating to product manufacture, sample preparation or analytical methodology (Williamson et al., 2005). They have a decisive influence on programmes recommending a healthy food. Food composition information on labels is subject to strict legal regulation in order to assure compliance with the law and protect consumers, including those aspects of food that affect health. In this respect, legal requirements relating to the use of nutrient profiles are regulated at the European level through the Regulation on Nutritional Labelling, 90/496/ECC (EC, 2008) and Regulation on Nutritional and Heath Claims made on Foods (Regulation 1924/2006) (EC, 2007). This Regulation lays down harmonized rules for the use of nutrition and health claims labelling. Food composition plays a central role in product optimization, product positioning and claim substantiation. There is an obvious need for good quality data on nutrient content (Roodenburg & Leene, 2007). As far as the authors are aware, there have been no studies that analyse (quantify) variation in the nutrient composition of different commercial meat products made by the meat industry at different times of year. The aim of the present work was therefore to examine the proximate composition, fatty acid profile, cholesterol, energy and mineral contents of several commercial meat products made and marketed at different times of year. In order to obtain a general overview, products with different composition (protein and fat levels) and processing conditions (lean-only cuts, ground meat, fresh, cooked, brined, etc.) and widely accepted by Spanish consumers were selected. This study paid special attention to over the year variability in nutritional properties and the consequences for labelling. 2. Materials and methods 2.1. Meat products Various commercial pork products with different characteristics and widely accepted by Spanish consumers were selected. These products were: “chorizo” (CH, Spanish fermented sausage), “longaniza” (LONG, fresh sausage); “lomo sajonia” (LSA, brined, pickled,

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smoked and cooked loin), “cinta de lomo” (CLO, brined and pickled loin), and “morcilla” (MOC, Spanish cooked blood sausage with onion). An innovative product was also studied, in this case a healthy cooked blood sausage (HBS, made with rice and olive oil). These commercial meat products were made by a meat processor (EMCESA, Toledo, Spain). To consider variation of meat product composition over the year, the study was carried out in three different months: April, June and September. They were selected from among the more representative of the different production levels taking into account the seasonal demand for some of these meat products. Upon arrival at our laboratory they were stored (2 °C ± 1) until the time came to prepare them for analysis (less than 24 h). Following removal of all non-edible parts, each type of product were homogenized to produce a representative sample and ensure the representativeness of subsample taken for analysis. In every case the homogenate was stored (2 °C ± 1) until analyzed (within 48 h of preparation). At least three commercial presentations (from different production runs) of each type of product were analyzed in each production time (month) studied. 2.2. Proximate analysis and energy values Moisture fat and ash contents were determined (AOAC, 2000) in triplicate. Protein content was measured in triplicate with a LECO FP2000 Nitrogen Determinator (Leco Corporation, St Joseph, MI, USA). Carbohydrates were estimated by difference. Starch was measured in triplicate (AOAC, 2000). Energy value was estimated from protein (×4 kcal/g), carbohydrate (×4 kcal/g) and fat (×9 kcal/g) contents for each product. 2.3. Fatty acid profile Fatty acids were determined by gas chromatography in three lipid extractions (Bligh & Dyer, 1959) of each sample. Boron trifluoride/ methanol was used for fatty acid methyl ester (FAME) preparation (Sánchez-Muniz, García Linares, García Arias, Bastida, & Viejo, 2003). A Shimadzu gas chromatograph (Model GC-2014, Kyoto, Japan) fitted with a capillary column SP™-2330 (60 m × 0.25 mm × 0.2 μm i.d.) (Supelco, Inc, Bellefonte, USA) and a flame ionisation detector (FID) was used. Injector and detector temperatures were 250 and 260 °C respectively, and the oven temperature was 140 °C for 5 min followed by an increase at a rate of 4 °C/min to 240 °C, which was held for 20 min. Fatty acids were identified by comparison with a known standard FAME mixture (Supelco, Alltech Associated, Inc. Deerfield, IL, USA). 2.4. Cholesterol content Cholesterol content was determined as reported by Serrano et al. (2005). Briefly, the fatty substances were extracted (in duplicate) by chloroform–methanol. Cholesterol content was determined from unsaponifiable extract following recovery of the sterol fraction, and further transformation into trimethyl-silyl ethers. These derivates were analysed by capillary-column gas chromatography (EEC, 1991). Betulin was used as an internal standard. 2.5. Minerals Samples were ashed in triplicate in a furnace, with temperature gradients between 105 and 500 °C. The ash was dissolved in 2 ml concentrated nitric acid and diluted to 100 ml with Milli-Q water. The minerals were determined on an atomic absorption spectrophotometer (Perkin-Elmer, Model 5100, Norwalk, Connecticut. USA). A hollow cathode lamp was used to determine Ca, Fe, Mg, Zn, Cu and Mn. Na and K were analysed by atomic emission (without a lamp). Analytical lines were selected following the criterion of maximum

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sensitivity and were free of spectral interferences. The analytical curve was determined for each element using standard solutions (Panreac Química, S.A.U. Barcelona. Spain). 2.6. Statistical analysis The effect of each production time on the different meat product components was tested by one-way ANOVA using the Statgraphics Plus 5.1(STSC, Inc. Rockville, MD, USA). Tukey's test was used post hoc to identify significant differences (P b 0.05) among means. Correlations were established between cholesterol content and fat and protein contents. 3. Results and discussion 3.1. Proximate analysis Traditional meat products were selected on the basis of their composition and processing conditions so as to encompass a broadly representative sample of commercially-available meat derivatives. Also, a reformulated traditional Spanish meat product was selected as an innovative, healthy choice. The products were sorted into two categories by protein content (Tables 1–6). The first group included those containing more than 14% protein content (fresh and Spanish fermented sausages, brined and pickled loin and brined, pickled, smoked and cooked loin); CLO presented the highest content of these (N18.5%). Blood sausages (MOC and HBS) presented the lowest protein content, both containing less than 8% (Tables 5 and 6). Products also differed clearly in terms of the presence of lipids (Tables 1–6). CH (Table 1) and MOC (Table 5) presented high fat content (N30%), while LONG (Table 2) had medium fat content (11– 14%) and LSA (Table 3), CLO (Table 4) and HBS (Table 6) low fat

Table 2 Composition of “longaniza” (LONG, fresh sausage). April Moisture (%) Protein (%) Fat (%) Ash (%) Carbohydrate (%) SFA (% total fatty acids) MUFA (% total fatty acids) PUFA (% total fatty acids) n−6 (% total fatty acids) n−3 (% total fatty acids) Trans (% total fatty acids) PUFA/SFA MUFA/SFA n−6/n−3 Cholesterol (mg/100 g) Fat/cholesterol Total calories (kcal/100 g) Calories from fat (kcal/100 g) Calories from fat (%) Calories from protein (kcal/100 g) Calories from protein (%) Fe (mg/100 g) Zn (mg/100 g) K (mg/100 g) Mg (mg/100 g) Ca (mg/100 g) Na (mg/100 g)

June

September

66.64a ± 0.03 16.05a ± 0.28 11.99a ± 0.24 2.75a ± 0.00 2.57a ± 0.01 37.10a ± 0.09 47.90a ± 0.33 14.40a ± 0.19 12.40a ± 0.21 1.10a ± 0.05 0.60a ± 0.07 0.39a ± 0.01 1.29ab ± 0.01 11.30a ± 0.19 32.70ab ± 2.54 0.37a ± 0.04 182.38a ± 1.09 107.91a ± 2.16

65.85b ± 0.06 14.85b ± 0.24 14.59b ± 0.23 2.53b ± 0.02 2.17ab ± 0.03 35.90b ± 0.15 48.60a ± 0.32 15.20b ± 0.07 10.70b ± 0.29 1.00a ± 0.07 0.30a ± 0.14 0.42a ± 0.02 1.35a ± 0.05 10.70a ± 0.21 25.65a ± 1.48 0.57b ± 0.04 199.45b ± 1.01 131.35b ± 2.10

69.97c ± 0.03 14.58b ± 0.32 11.19a ± 0.09 2.54b ± 0.03 1.71b ± 0.28 37.90a ± 0.26 45.80b ± 0.15 15.70b ± 0.32 13.20a ± 0.28 1.20a ± 0.07 0.60a ± 0.07 0.41a ± 0.01 1.21b ± 0.05 11.00a ± 0.12 35.00b ± 0.71 0.32a ± 0.01 165.90c ± 0.68 100.73a ± 0.79

59.16a ± 0.83 64.20a ± 1.13

65.86b ± 0.72 59.40b ± 0.96

60.71a ± 0.23 58.34b ± 1.26

35.20 ± 0.83 0.79a ± 0.09 1.85a ± 0.02 278.35ab ± 10.06 17.00a ± 0.16 6.80a ± 0.35 752.02a ± 6.41

29.78 ± 0.63 0.82a ± 0.10 1.66b ± 0.05 299.95a ± 27.4 16.47a ± 0.035 6.50a ± 0.66 796.65b ± 22.1

35.16 ± 0.90 0.88a ± 0.09 1.95c ± 0.06 251.67b ± 11.6 16.55a ± 0.41 6.20a ± 0.52 761.69a ± 19.81

Different letters in the same row indicate significant differences (P b 0.05). ±standard deviation. Cu and Mn contents are lower than quantification limit.

content (1–7%). Moisture varied from 75% (LSA) to 41–45% in the case of CH and MOC (Tables 1–6). Ash content ranged between 2% (LONG, MOC, HSB) and 4.5% in LSA, which is consistent with the latter's higher Table 3 Composition of “lomo sajonia” (LSA, brined, pickled, smoked and cooked pork loin).

Table 1 Composition of “chorizo” (CH, spanish fermented sausage). April Moisture (%) Protein (%) Fat (%) Ash (%) Carbohydrate (%) SFA (% total fatty acids) MUFA (% total fatty acids) PUFA (% total fatty acids) n−6 (% total fatty acids) n−3 (% total fatty acids) Trans (% total fatty acids) PUFA/SFA MUFA/SFA n−6/n−3 Cholesterol (mg/100 g) Fat/cholesterol Total calories (kcal/100 g) Calories from fat (kcal/100 g) Calories from fat (%) Calories from protein (kcal/100 g) Calories from protein (%) Fe (mg/100 g) Zn (mg/100 g) K (mg/100 g) Mg (mg/100 g) Ca (mg/100 g) Na (mg/100 g)

June

April September

42.45a ± 0.03 15.57a ± 0.08 37.33a ± 0.22 3.42a ± 0.03 1.21a ± 0.23 37.20a ± 0.28 48.60a ± 0.31 13.90a ± 0.24 12.10a ± 0.40 0.80a ± 0.14 0.30a ± 0.00 0.37a ± 0.02 1.30a ± 0.02 15.10a ± 0.74 90.95a ± 1.20 0.41a ± 0.01 403.18a ± 1.34 336.01a ± 1.97 83.34a ± 0.21 62.30a ± 0.31

41.71b ± 0.03 17.61b ± 0.10 35.30b ± 0.30 3.61b ± 0.03 1.76ab ± 0.40 37.30a ± 0.11 48.30a ± 0.09 14.30a ± 0.35 12.10a ± 0.40 1.00ab ± 0.10 0.30a ± 0.00 0.38a ± 0.01 1.29a ± 0.01 12.10b ± 0.54 103.50a ± 2.83 0.34a ± 0.01 395.24b ± 1.52 317.74b ± 2.74 80.39b ± 0.38 70.44b ± 0.40

43.83c ± 0.06 14.53c ± 0.20 35.50b ± 0.19 3.38a ± 0.02 2.75b ± 0.02 35.90b ± 0.24 47.60a ± 0.40 16.20b ± 0.29 13.80b ± 0.30 1.20b ± 0.14 0.30a ± 0.00 0.45a ± 0.03 1.32a ± 0.01 11.50b ± 0.62 92.40a ± 9.33 0.39a ± 0.04 388.68c ± 0.80 319.54b ± 1.72 82.21a ± 0.07 58.13c ± 0.83

15.45a ± 0.02 1.44a ± 0.14 1.70a ± 0.03 337.47a ± 16.4 18.42a ± 0.22 14.75a ± 1.67 938.00a ± 18.0

17.82b ± 0.03 1.07a ± 0.03 1.62a ± 0.04 390.38b ± 20.8 20.56b ± 0.24 11.87b ± 0.56 1091.66b ± 42.6

15.45a ± 0.24 1.13a ± 1.36 1.64a ± 0.11 256.01c ± 8.08 17.88a ± 0.56 14.00ab ± 1.18 954.14a ± 40.9

Different letters in the same row indicate significant differences (P b 0.05). ±standard deviation. Cu and Mn contents are lower than their quantification limit.

June

September

Moisture (%) 76.64a ± 0.02 74.68b ± 0.08 75.07c ± 0.02 Ash (%) 4.29a ± 0.00 4.51b ± 0.00 4.71c ± 0.01 Protein (%) 16.07a ± 0.01 15.64b ± 0.06 15.95a ± 0.00 Fat (%) 1.71a ± 0.01 3.06b ± 0.04 2.46c ± 0.02 Carbohydrates (%) 1.27a ± 0.01 2.11b ± 0.08 1.79c ± 0.01 SFA (% total fatty acids) 40.60b ± 0.12 43.20c ± 0.51 38.10a ± 0.39 MUFA(% total fatty acids) 45.10a ± 0.27 40.90b ± 0.39 40.50b ± 0.28 PUFA (% total fatty acids) 13.60a ± 0.17 15.50b ± 0.22 20.90c ± 0.49 n−6 (% total fatty acids) 10.90a ± 0.29 13.30b ± 0.19 16.50c ± 0.37 n−3 (% total fatty acids) 0.80b ± 0.14 0.80b ± 0.14 1.40a ± 0.18 Trans (% total fatty acids) 0.60a ± 0.07 0.30a ± 0.14 0.60a ± 0.07 PUFA/SFA 0.33b ± 0.05 0.36b ± 0.04 0.55a ± 0.10 MUFA/SFA 1.11a ± 0.05 0.95a ± 0.07 1.06a ± 0.02 n−6/n−3 13.60b ± 0.04 16.60a ± 0.26 11.80c ± 0.26 Cholesterol (mg/100 g) 37.75a ± 1.76 19.95b ± 1.06 38.00a ± 0.71 Fat/colesterol 0.05a ± 0.00 0.15b ± 0.01 0.06c ± 0.00 Total calories (kcal/100 g) 84.83a ± 0.14 98.54b ± 0.50 93.18c ± 0.16 Calories from fat (kcal/ 15.43a ± 0.06 27.54b ± 0.38 22.18c ± 0.19 100 g) 27.94b ± 0.24 23.81c ± 0.16 Calories from fat (%) 18.19a ± 0.04 Calories from protein 64.30a ± 0.03 62.56b ± 0.23 63.80a ± 0.00 (kcal/100 g) 63.49b ± 0.55 68.47c ± 0.12 Calories from protein (%) 75.79a ± 0.09 Fe (mg/100 g) 0.54a ± 0.06 0.58a ± 0.12 0.59a ± 0.03 Zn (mg/100 g) 1.05a ± 0.18 1.00a ± 0.07 1.15a ± 0.03 K (mg/100 g) 487.40a ± 79.3 473.47a ± 37.53 413.54a ± 27.6 Mg (mg/100 g) 18.97a ± 2.48 18.12a ± 0.46 18.30a ± 0.65 Ca (mg/100 g) 10.95a ± 0.70 13.55b ± 1.39 13.57b ± 0.33 Na (mg/100 g) 1187.12a ± 186 1347.60a ± 45.2 1337.45a ± 92.4 Different letters in the same row indicate significant differences (P b 0.05). ±standard deviation. Cu and Mn contents are lower than quantification limit.

F. Jiménez-Colmenero et al. / Food Research International 43 (2010) 2378–2384 Table 4 Composition of “cinta de lomo” (CLO, brined and pickled pork loin).

Moisture (%) Ash (%) Protein (%) Fat (%) Carbohydrate (%) SFA (% total fatty acids) MUFA (% total fatty acids) PUFA (% total fatty acids) n−6 (% total fatty acids) n−3 (% total fatty acids) Trans (% total fatty acids) PUFA/SFA MUFA/SFA n−6/n−3 Cholesterol (mg/100 g) Fat/colesterol Total calories (kcal/100 g) Calories from fat (kcal/100 g) Calories from fat (%) Calories from protein (kcal/100 g) Calories from protein (%) Fe (mg/100 g) Zn (mg/100 g) K (mg/100 g) Mg (mg/100 g) Ca (mg/100 g) Na (mg/100 g)

Table 6 Composition of healthy cooked blood sausage (HBS, elaborated with rice and olive oil).

April

June

September

74.75a ± 0.02 3.04a ± 0.07 18.74a ± 0.03 2.99a ± 0.03 0.47a ± 0.06 39.00b ± 0.17 41.90a ± 0.27 18.60b ± 0.45 15.90b ± 0.29 0.80a ± 0.12 0.30a ± 0.14 0.47a ± 0.06 1.07a ± 0.07 19.90c ± 0.39 36.50a ± 3.82 0.08a ± 0.01 103.80a ± 0.01 26.95a ± 0.32 25.97a ± 0.31 74.96a ± 0.01

72.57b ± 0.06 2.44b ± 0.00 20.56b ± 0.06 3.35a ± 0.69 1.07a ± 0.70 37.80a ± 0.28 48.10c ± 0.19 13.60a ± 0.28 11.40a ± 0.19 1.00a ± 0.02 0.60a ± 0.07 0.36a ± 0.02 1.27a ± 0.19 11.40b ± 0.20 16.50b ± 1.41 0.20b ± 0.02 116.71b ± 3.64 30.15a ± 6.19 25.76a ± 4.50 82.27b ± 0.06

66.22c ± 0.02 2.74c ± 0.00 18.90a ± 0.13 7.31b ± 0.01 4.82b ± 0.09 39.90b ± 0.21 46.20b ± 0.16 13.20a ± 0.37 10.70a ± 0.39 1.10a ± 0.09 0.60a ± 0.07 0.33a ± 0.04 1.19a ± 0.01 9.70a ± 0.39 25.00c ± 2.12 0.29c ± 0.01 160.69c ± 0.03 65.79b ± 0.13 40.94b ± 0.09 75.60a ± 0.51

72.21a ± 0.10 0.68a ± 0.18 1.16a ± 0.30 345.57a ± 80.1 19.27a ± 4.55 6.37a ± 1.35 637.32a ± 18.2

70.52a ± 1.98 0.61a ± 0.08 1.24a ± 0.08 395.85a ± 32.0 23.75a ± 0.24 7.05a ± 0.17 629.60a ± 24.9

47.05b ± 0.31 0.75a ± 0.04 1.62b ± 0.05 318.76a ± 11.7 23.20a ± 0.71 6.55a ± 0.49 571.81a ± 30.5

Different letters in the same row indicate significant differences (P b 0.05). ±standard deviation. Cu and Mn contents are lower than quantification limit.

mineral content (Tables 1–6). Carbohydrate concentrations were higher than the rest in both blood sausages (mainly in the form of starch), particularly in HBS, whose formulation included vegetable

Table 5 Composition of “morcilla” (MOC, cooked blood sausage with onion). April Moisture (%) Protein (%) Fat (%) Ash (%) Carbohydrate (%) Starch (%) SFA (% total fatty acids) MUFA (% total fatty acids) PUFA (% total fatty acids) n−6 (% total fatty acids) n−3 (% total fatty acids) Trans (% total fatty acids) PUFA/SFA MUFA/SFA n−6/n−3 Cholesterol (mg/100 g) Fat/cholesterol Total calories (kcal/100 g) Calories from fat (kcal/100 g) Calories from fat (%) Calories from protein (kcal/100 g) Calories from protein (%) Fe (mg/100 g) Zn (mg/100 g) K (mg/100 g) Mg (mg/100 g) Ca (mg/100 g) Cu(mg/100 g) Mn (mg/100 g) Na (mg/100 g)

June

September

a

41.60 ± 0.06 8.04a ± 0.09 37.63a ± 0.30 2.02a ± 0.00 10.71a ± 0.32 7.07 a ± 0.02 36.70a ± 0.27 46.30b ± 0.21 16.70a ± 0.16 14.60b ± 0.12 1.10a ± 0.05 0.30a ± 0.00 0.45a ± 0.05 1.26a ± 0.05 13.20a ± 0.32 61.65a ± 1.34 0.61a ± 0.01 413.67a ± 1.73 338.67a ± 2.67 81.87a ± 0.3 32.18a ± 0.37

42.08 ± 0.06 7.49b ± 0.06 36.12b ± 0.10 2.33b ± 0.01 11.96b ± 0.09 9.43 b ± 0.21 38.00a ± 0.25 46.10b ± 0.27 15.70a ± 0.27 13.40a ± 0.17 1.10a ± 0.05 0.30a ± 0.00 0.41a ± 0.07 1.21a ± 0.05 12.20a ± 0.26 37.00b ± 0.71 0.98b ± 0.02 402.92b ± 0.77 325.08b ± 0.89 80.68a ± 0.07 29.98b ± 0.25

a

b

7.78 ± 0.05 10.24a ± 0.23 0.42a ± 0.02 136.15a ± 8.94 15.37a ± 0.15 25.97a ± 1.61 0.12a ± 0.06 0.12a ± 0.01 583.97a ± 10.9

b

7.44 ± 0.05 8.34b ± 0.12 0.51a ± 0.02 235.90b ± 29.8 18.20b ± 0.15 18.42b ± 0.71 0.10b ± 0.05 0.01b ± 0.00 694.17b ± 30.8

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44.98c ± 0.04 7.55b ± 0.03 31.67c 0.35 2.15a ± 0.06 13.65c 0.28 8.60 ab ± 1.24 37.40a ± 0.12 43.90a ± 0.18 18.40a ± 0.24 15.90c ±0.19 1.30a ± 0.12 0.30a ± 0.00 0.49a ± 0.05 1.17a ± 0.06 12.20a ± 0.22 67.50c ± 0.71 0.47c ± 0.00 369.83c ± 2.16 285.03c ± 3.18 77.07b ± 0.41 30.20b ± 0.11

Moisture (%) Ash (%) Protein (%) Fat (%) Carbohydrate (%) Starch (%) SFA (% total fatty acids) MUFA (% total fatty acids) PUFA (% total fatty acids) n−6 (% total fatty acids) n−3 (% total fatty acids) Trans (% total fatty acids) PUFA/SFA MUFA/SFA n−6/n−3 Cholesterol (mg/100 g) Fat/cholesterol Total calories (kcal/100 g) Calories from fat (kcal/100 g) Calories from fat (%) Calories from protein (kcal/100 g) Calories from protein (%) Fe (mg/100 g) Zn (mg/100 g) K (mg/100 g) Mg (mg/100 g) Ca (mg/100 g) Cu(mg/100 g) Mn (mg/100 g) Na (mg/100 g)

April

June

September

59.59a ± 0.01 1.92a ± 0.00 5.47a ± 0.01 7.18a ± 0.01 25.83a ± 0.06 21.15 a ± 0.34 18.20a ± 0.24 74.50b ± 0.26 6.90a ± 0.12 6.20a ± 0.11 0.70a ± 0.02 0.30a ± 0.00 0.38a ± 0.03 4.09a ± 0.31 8.86a ± 0.18 39.85a ± 0.07 0.24 ± 0.00 189.84a ± 0.05 64.62a ± 0.13 34.04a ± 0.06 21.90a ± 0.31

60.50b ± 0.00 2.06b ± 0.02 5.44a ± 0.19 6.75 b ± 0.06 25.24a ± 0.26 16.48 b ± 1.16 20.60b ± 0.26 69.90a ± 0.30 9.20b ± 0.21 8.00b ± 0.27 0.80a ± 0.05 0.30a ± 0.00 0.45a ± 0.02 3.39a ± 0.18 10.00b ± 0.13 17.90b ± 1.56 0.38 ± 0.03 183.50b ± 0.21 60.75b ± 0.51 33.11a ± 0.24 21.78a ± 0.76

61.77c ± 0.01 2.13b ± 0.03 7.58b ± 0.08 7.52c ± 0.11 20.99b ± 0.22 20.2 a ± 0.46 20.20b ± 0.28 70.80a ± 0.26 8.50b ± 0.21 7.40b ± 0.14 0.70a ± 0.02 0.30a ± 0.00 0.42a ± 0.05 3.50a ± 0.10 10.57b ± 0.23 22.00b ± 1.41 0.34 ± 0.01 182.01c ± 0.45 67.72c ± 0.98 37.21b ± 0.45 30.32b ± 0.34

11.54a ± 0.17 8.05a ± 0.29 0.46a ± 0.06 162.40a ± 30.3 16.05a ± 0.46 48.77a ± 1.67 0.12a ± 0.01 0.15a ± 0.02 538.17a ± 12.9

11.87a ± 0.40 8.20a ± 0.18 0.37b ± 0.01 170.40a ± 12.0 17.75b ± 0.55 70.55b ± 4.05 0.10a ± 0.02 0.02b ± 0.00 623.02b ± 4.38

16.66b ± 0.15 6.88b ± 0.37 0.44ab ± 0.03 161.79a ± 11.8 19.04b ± 1.30 20.97c ± 0.97 0.10a ± 0.01 0.31c ± 0.01 784.29c ± 30.7

Different letters in the same row indicate significant differences (P b 0.05). ±standard deviation.

ingredients (Tables 5 and 6). All the other products presented lower starch content (b1.0%) (results not shown). Over the year variation of proximate analysis (P b 0.05) was observed in all products. Maximum moisture variations between production times ranged between 2% (LSA) and 8.5% (CLO), with an average variation of 3.7%. In the case of protein content the variations ranged from 3% in CH to 0.4% in LSA. The average variation was 1.6%. Similarly, fat content variability ranged from 6% (MOC) to 0.7% (HBS), with an average variation of around 3%. This means that the production time variability in moisture and fat contents is roughly double that of the proportion of protein; however, no relationship with the type of product has yet been determined. The largest variations were found in CLO and the smallest in LSA; both products were made with whole pieces of meat unlike all the other meat derivatives studied, which presented varying degrees of structural disintegration. It seems clear that the variability of raw materials can be better compensated by controlled combination of these materials, other than in the case of lean-only cuts, where the inter animal variability has a greater impact. 3.2. Fatty acid composition

c

8.17 ± 0.02 6.49c ± 0.11 0.71b ± 0.11 119.88a ± 32.8 14.56a ± 1.02 23.55c ± 0.89 0.10b ± 0.02 0.26c ± 0.01 561.40c ± 6.40

Different letters in the same row indicate significant differences (P b 0.05). ±standard deviation.

The fatty acid profile (Tables 1–6) is important since dietary fat has health implications resulting from the presence of saturated (SFA), monounsaturated (MUFA) and polyunsaturated (PUFA) fatty acids and the proportion between them. Because of their importance, lipids are among the bioactive components (functional ingredients) that have received most attention, particularly (in quantitative and qualitative terms) with respect to the development of healthier meat products (Jiménez-Colmenero, 2007). The fatty acid profiles (presented by types of fatty acids in order to give a clearer, more

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concise picture) of the products considered fall into two categories (Tables 1–6). In the cases of traditional meat products (CH, LONG, LSA, CLO and MOC), fatty acids proportions were, with some differences between products, consistent with the pork fat used to make them. SFA made up between 36 and 43% of these products; palmitc acid accounted for 23–24% and stearic acid for 12–15%. Although SFA are believed to present the greatest risk factor because of their hypercholesterolaemic effect, they do not all act in the same way (Williamson et al., 2005). While stearic acid appears to have no effect on cholesterol levels, the greater atherogenic effect is produced by palmitic and especially myristic acids (1.2–1.5%), which together account for approximately 25% of total fatty acids. The presence of MUFA varies between 40% in LSA (Table 3) and 48% in Spanish fermented sausage or fresh sausage (Tables 1 and 2), the main component being oleic acid (39–44%). These products also contain considerable amounts of PUFA (13–20%), the principal component being linoleic acid, with percentages of up to 11–16%. If we consider the overall percentage of unsaturated fatty acids for these products, i.e. MUFA + PUFA (ranging from 56 to 63%, Tables 1–5), a general assertion that these products are high in saturates does not seem reasonable. And all the more so if we consider that the percentage of SFA that constitutes a risk factor (total SFA less stearic acid) is approximately 25%. The PUFA/SFA ratio and the n6/n3 PUFA ratio are the main parameters currently used to assess the nutritional quality of the lipid fraction of food. Nutritional guidelines recommend a PUFA/ SFA ratio above 0.4–0.5 (Wood et al., 2003); this varied in the products analysed from 0.3 to 0.6 (Tables 1–5). In order to improve the health status of humans, it has been recommended that the n6/n3 PUFA ratio, which in meat products studied ranged from 10 to 19 (Tables 1–5), should be less than 4 (Wood et al., 2003). In the case of healthy blood sausage formulated with olive oil (HBS), the lipid composition was different. Numerous researchers are endeavouring to optimize the amounts of lipids and the fatty acid profiles of various meat products in order to achieve a more convenient composition related to nutrient intake goals. A variety of non-meat fats of plant and marine origin have been added to different meat products as partial substitutes for meat fats (Jiménez-Colmenero, 2007). Of vegetable oils, olive is the one that has received most attention, chiefly as a source of MUFA. The intake of MUFA may be protective against age-relate cognitive decline and Alzheimer's disease. Olive oil consumption has benefits for breast and colon cancer prevention (López-Miranda, Pérez-Martinez, & Pérez-Jiménez, 2006). Healthy blood sausage with a small percentage of fat (around 7%) presents a very different fatty acid profile from all the other products considered (Tables 1–6). Compared to these products, HBS contained less than half the concentrations of SFA and PUFA and a much higher proportion of MUFA. As reported elsewhere (JiménezColmenero, 2007), olive oil increases MUFA concentrations in meat products without greatly affecting ratios based on the relative amounts of SFA or PUFA (Tables 1–6). Production time variations (P N 0.05) were generally observed in the fatty acid proportions of the different meat products (Tables 1–6). The variations were largest in lean-only cut products (LSA and CLO), followed by the blood sausages (MOC and HBS) (Tables 1–6). Consequently, the fat content was not a determining factor in the observed changes in fatty acid profiles. The greatest variation (over 5%) in SFA was observed in LSA (Table 3), while in all the other products it ranged between 1.3 and 2.1%. In the case of MUFA the greatest variation was found in CLO (over 6%); it was less in LSA and HBS (4.6%) and lower than 3% in all the other samples (Tables 1–6). There were major production time variations in PUFA in lean-only cut products (over 5%) (Tables 3 and 4); the changes in PUFA were essentially due to variations in n−6 PUFAs, the principal factor responsible for the changes in the n−6/n−3 PUFA ratio. However, over the year changes in other fatty acid ratios (PUFA/SFA and MUFA/ SFA) were not significant (Tables 1–6). Trans fatty acids ranged

between 0.3 and 0.6%, and their proportions were not affected by the type of product or the time of production (Tables 1–6). 3.3. Cholesterol content There are several aspects that have to be considered with regard to the cholesterol content of studied meat products (Tables 1–6). With the exception of the Spanish fermented sausage (CH), the products analysed all presented relatively low cholesterol concentrations, as compared to meat products of similar natures (Moreiras, Carbajal, Cabrera, & Cuadrado, 2006), with average values ranging between 55 mg/100 g in MOC and 23 mg/100 g in HBS (Tables 1–6). High production time variation was observed in cholesterol content, but there was not evident relationship with the type of product or fat content (Tables 1–6). This variability makes it difficult to estimate levels of cholesterol intake associated with these products. Consumption of 100 g of these products means an intake of between 30 and 95 (mean values) mg of cholesterol, which is between 10 and 30% of recommended intake b300 mg/day (WHO, 2003). The correlation coefficient for the relationship between fat and cholesterol contents of the meat products was 0.809 (P b 0.001), rising to 0.859 (P b 0.001) in the case of the relationship between cholesterol and the sum of fat and protein contents. In both cases there was a moderately strong relationship among these variables. The fat/ cholesterol ratio was generally high when the percentage of fat in the products was high (Tables 1–6), because this ratio is higher in fatty than in lean tissues (Honikel & Arneth, 1996). However, Chizzolini, Zanardi, Dorigoni, and Ghidini (1999) reported that in meat products higher fat contents would mean higher cholesterol only in some cases. This is because the cholesterol content of meat products depends not only on the fat content but also on the different muscles (red or white) used; then again, ingredients other than muscle tissue, such as offal, can also affect cholesterol content (Chizzolini et al., 1999). This explains why the best possibility of reducing cholesterol is essentially through the substitution of meat raw materials (fatty tissue and lean meat) with others (generally of vegetable origin) that do not contain cholesterol. 3.4. Energy value The calories in the diet are an important factor in terms of both magnitude and origin. According to dietary recommendations proposed by a number of scientific authorities and nutritional organizations including the World Health Organisation (WHO, 2003), dietary fat intake should ideally account for between 15% and 30% of total diet energy, 10–15% of calorie intake should be from protein and 55–75% from carbohydrates. These recommendations in fact refer to the overall diet, but meat and meat products are some of the most important sources of dietary nutrients in western countries, including Spain (MARM, 2008). Meat contribution to caloric intake is estimated to range from 10 to 20% of total calories in most developed countries (Chizzolini et al., 1999). Of the products analysed, LSA supplied less than 100 kcal/100 g (Table 3), while CH and MOC supplied around 400 kcal/100 g (Tables 1 and 5). The contribution of fat to the energy value of both products (CH and MOC) was greater, with almost 80% of the total caloric value fat-derived. At the opposite extreme are LSA, CLO and HBS (Tables 3, 4 and 6), where the proportion of the energy value derived from fat was lower (25–40%) and that derived from protein was higher (N70%), in some cases contributing more than fat (Tables 1–6). The significant production time variations of energy values in different meat products were generally associated with changes in their fat contents. Carbohydrates generally contribute little to the calorific value of meats (Chizzolini et al., 1999). However, although this was true of most of the products analysed, it was not so in the case of MOC and

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HBS, where carbohydrates (mainly from onion and rice) accounted for 10–50% of the calorific value (Tables 5 and 6). 3.5. Minerals Meat is an important dietary source of bioavailable minerals and trace elements. Since meat products contain meat and non-meat ingredients, they are likely to contain different micronutrients profile. The concentration of iron varied widely in the products analysed (Tables 1–6). Both blood sausages (MOC and HBS, Tables 5 and 6) contained large amounts (around 6–10 mg/100 g), while in all the other products contained roughly 8–10 times less, ranging from 0.54– 0.59 mg/100 g in LSA (Table 3) to 1.1–1.4 mg/100 g in CH (Table 1). A 100 g portion of MOC or HBS would supply 40–70% of the recommended daily allowance (RDA, 14 mg/100 g) of Fe (EC, 2008), and therefore their labels could state that they contain significant amounts of iron, which is moreover highly bioavailable. Iron deficiency produces anaemia, which is one of the principal public health problems. In Spain, dietary iron intake in 2006 did not exceed 80% of the recommended level for women aged 20–39 (MARM, 2008). Except for the blood sausages (MOC and HBS), where Zn levels were around 0.5 mg/100 g, the products analysed all contained between 1 and 2 mg/100 g of Zn (Tables 1–6), which is very much consistent with the data reported for products of similar natures (Moreiras et al., 2006). In Spain 26% of dietary zinc comes from meat or meat products (MARM, 2008). LONG and CH are significant sources of Zn, 100 g of which supplies more than 15% of the RDA (10 mg/ 100 g) (EC, 2008). Although zinc is an essential mineral in the diet, intake levels have been falling in some countries in recent years (Mulvihil, 2004), and low zinc intake has been identified as a problem for some population groups (Williamson et al., 2005). Meat and meat derivatives are among the principal sources of dietary potassium, which plays an essential part in energy metabolism and membrane transport. In Spain meats supply 13% of dietary K (MARM, 2008). Potassium concentrations in the meat products ranged from N400 mg/100 g (LSA, Table 3) to generally less than 180 mg/100 g (MOC and HBS, Tables 5 and 6). This means that 100 g of any one of several of these products would supply more than 15% of the RDA (2000 mg/100 g) of potassium (EC, 2008). Levels of magnesium in the products ranged from 14 to 23 mg/100 g (Tables 1–6), similar to those reported by Moreiras et al. (2006). The CH was different in this respect (Table 1), with a Mg concentration (18–20 mg/100 g) above the values previously described (MSC, 1995; Moreiras et al., 2006). The studied products did not constitute a significant natural source of calcium (Tables 1–6), which is normal in this kind of muscle based foods (MSC, 1995; Moreiras et al., 2006). Some of the products also contained useful amounts of Mn and Cu (Tables 1–6). A large percentage of the population possess a hereditary predisposition to high arterial blood pressure, the incidence of which is further affected by excess weight and high sodium intake. Sodium comes from a wide variety of foods, among them meat and meat derivatives. Estimations taking eating habits into account suggest that approximately 27% of sodium intake by consumers in Spain comes from meat and meat derivatives. The products analysed here contained significant concentrations of sodium, which were however similar to those found in meat derivatives of a similar nature (Moreiras et al., 2006). Levels were highest in CH and LSA, with values of around 1000 and 1300 mg/100 g respectively (Tables 1–6), while levels ranged between 500 and 800 mg/100 g in all the other products. The amount of sodium that they supply is therefore a major proportion of the amount indicated by dietary guidelines and nutritional recommendations (b2 g/day) (WHO, 2003). Production time variation in mineral composition varies depending on the meat product and the mineral. With the exception of the blood sausages (Tables 5 and 6), there were no variations (P N 0.05) in Fe content (Tables 1–4). In ground meat products the concentrations

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of the other minerals considered were affected, if to a different extent, by the production time. In contrast to ground meat products, leanonly cuts (LSA and CLO) did not generally undergo changes (P N 0.05) in mineral content (Tables 3 and 4). Production time variations in sodium content (P b 0.05) were observed only in ground products (CH, HBS, MOC, LONG, Tables 1–6); they were not significant in LSA or CLO. 3.6. Considerations regarding nutritional labelling of products In the light of European Union labelling regulations (EC, 2008) regarding nutritional properties and the calculation of what constitutes a significant amount (15% of the RDA in 100 g in the case of vitamins and minerals), several of the products analysed may be considered significant sources of Fe, Zn and K. Even in the case of the blood sausages, Fe content was higher than 30% of the RDA, and therefore there is a basis for a claim of high Fe content. However, the changes in some mineral contents as affected by the production time could affect the validity of such claims. For instance, 100 g of CLO would supply between 11 and 16% of the RDA of zinc, which means that it cannot be considered a significant source throughout the range of concentrations; the same applies to potassium in Spanish fermented sausages (CH). And again, the presence of saturated fat and sodium can affect the possibility of health claims on the labels of some of these products. The maximum levels of sodium (salt) and saturated fats with which nutrition and health claims for meat or meat-based products are allowed are 700 mg and 5 g per 100 g respectively of finished products (EC, 2009). Several of the products analysed, e.g. CH, LONG and LSA, contained more than the maximum allowance (Tables 1–3). In other products on the other hand (CLO, MOC and HBS), Na values were somewhere below the limit (Tables 4– 6), although in at least one case (HBS) the limit was exceeded as a consequence of time-dependent variation (Table 6). The lipid contents—and hence the saturated fat levels—of the products were generally affected by the production time (Tables 1–6). High fat products such as CH and MOC contained more than 10 g/100 g of saturated fats, while in low-fat products such as LSA, CLO and HBS the saturated fats levels were well below the allowable limit. In mediumfat content products like LONG (Table 2), changes in composition can raise or lower saturated fat values by 5 g/100 g. 4. Conclusions In conclusion, commercial meat products made at different times of year present significant variations in their nutritional profiles. This variability affects the estimation of current dietary intake of some components, and this has consequences for the nutritional labelling of some products. It is important not only in terms of the minimum amount of healthy nutrients, but also in terms of maximum levels of less healthy nutrients. Limiting nutrient composition production time variations requires a more precise control of production system (ingredients and processing factors). Although this study considers a limited number of products, and the generalization of these results must be done carefully, the impact of its findings should be taken into account as they highlight an important issue of great interest to the processed meat industry. Like any other foods, these products should be judged in the context of a balanced diet and in appropriate quantities. And in that context it is essential to keep in mind that foods today not only supply the organism's basic nutritional needs but also perform a key function in consumers' quality of life. Acknowledgments The authors would like to thank EMCESA for supplying the meat products and for its assistance in the study. Thanks are also due to Programa Consolider-Ingenio 2010:CARNISENUSA (CSD2007-00016).

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