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Nutritional evaluation of sausages containing chick pea flour (Cicer arietinum)
Meat Science 15 (1985) 31-35
NulLritional Evaluation of Sausages Containing Chick Pea Flour (Cicer arietinum) M. M. Verma, R. J. Neale & D. A. Ledward School of Agriculture, University of Nottingham, Sutton Bonington, Loughborough, Leics. LEI2 5RD, Great Britain (Received: 8 November, 1984)
S UMMA R Y Nutritional evaluation ojprotein quality was carried out on English-type fi'e:¢h skinless pork sausages in which 30 % of the protein had been replaced by chick pea flour, Net protein utilisation, biological value and protein efficiency ratio were unaffected by 30 % meat protein replacement. Comparison of the amino acid composition with 1he biological values suggested some reduction in amino acid availability due to cooking.
INTRODUCTION Recent work from this laboratory has investigated the feasibility of replacing meat (mutton, pork or beef) in comminuted meat products by varying levels of chick pea flour (CPF) (Cicer arietinum). Both subjective and objective criteria were employed and results showed that levels of substitution up to 30~o protein replacement could be made without adversely affecting product acceptability. Later work, however, showed that it was necessary to heat CPF to 80 °C for 1 h to prevent discoloration of raw sausages caused by lipid peroxidation on storage (Verma et al., 1984). In view of this work and the possible effects on nutritional value of the final product it was decided to investigate the influence of replacing meat by CPF on the protein quality of sausages measured by both amino acid analysis a n d / n vivo feeding trials with rats. 31
Meat Scwnce 0309-1740/85/$03.30 i~" Elsevier Applied Science Publishers Ltd, England, 1985. Printed in Great Britain
32
M. M. Verrna, R. J. Neale, D. A. Ledward
MATERIALS A N D M E T H O D S Pork sausages were prepared according to published methods (Verma et al., 1984) based on an initial composition of 9 ~o protein, 18 % fat, 56-5 % water, 15 % binder and 1.5 ~o salt. Control sausages had no C P F added. Two further samples of sausages were also prepared containing 30~, replacement of meat proteins by (a) C P F heated at 80°C for 1 h and (b) unheated CPF. All sausages were then shallow-fried at 150°C for 10min prior to chopping, freeze-drying, powdering and storage at 0 °C in moisture-proof plastic bags. The net protein utilisation (NPU) of the sausage protein was determined on rats of the Wistar strain by the method of Miller & Bender (1955) modified by grouping animals in separate cages rather than in groups of four. After weaning at 21 days the rats were fed on a basal casein diet so that they weighed between 40-45 g at the beginning of the feeding trial. The protein-free diet consisted of 150 g/kg D-glucose, 200 g/kg maize oil (including vitamins A, D, E and K), 11 g/kg vitamin B mix (Payne & Stewart, 1972), 50g/kg mineral salt mix (Payne & Stewart, 1972) and 589 g/kg maize starch. The sausage meat (containing both protein and oil) replaced part Qf the maize starch and maize oil such that each diet contained 100 g/kg total protein and 200 g/kg total fat. Rats were fed for 10 days ad libitum on all diets and at the end of the feeding period were killed with CO 2 and weighed. The carcasses were dissolved in 200 ml of 2 M NaOH by heating in a boiling water bath. The total weight of the slurry was obtained and its nitrogen content determined by the macro-Kjeldahl method. Faeces voided by the animals were collected, dried to constant weight at 105°C and milled to a fine powder with pestle and mortar, and the nitrogen content determined. N P U , true nitrogen digestibility (TD) and biological value (BV) were calculated as described (Miller & Bender, 1955). Protein efficiency ratio (PER) over 10 days was calculated as previously described. Amino acid analysis Freeze-dried cooked sausage samples (prepared as described) were left overnight at 105°C and defatted using the Soxhlet method (overnight soaking followed by 8 h continuous extraction). About 0.5 g of defatted samples were refluxed with 300ml 6M HCI for 22h in a nitrogen
Nutritional evaluation of sausages containing chick pea flour
33
atmosphere. The cooled digests were filtered and made up to 500 ml with distilled water. To 10ml of the diluted hydrolysate, l ml of 1.0M norleucine was added and the whole evaporated to dryness, under vacuum at not more than 37 °C. A few millilitres of distilled water were then added and the mixture again evaporated to dryness. The residue was dissolved in 5 ml li'Lhium citrate buffer, millipore filtered (0.2 mm) and stored at 0 °C. Cystine and cysteine were determined as cysteic acid following performic acid oxidation (Hirs, 1967). Amino acid analysis was performed using an LKB 4400 Amino Acid Analyser. Tryptophan was not determined. Calculations
BV=
NPU TD
The amino acid score was calculated by the following formula mg amino acid in test protein mg amino acid in reference protein
x
100
It is the lowest score obtained for any of the essential amino acids in the test proteins (i.e. the most limiting amino acid: FAO/WHO, 1973).
RESULTS AND DISCUSSION The amino acid composition of the sausages with and without CPF is shown in Table 1. In general all the amino acids, excepting valine and methionine and cystine (cysteic acid) are in excess of the F A O / W H O recommended score and the first limiting amino acid appears to be valine for the controls and the sausages containing the unheated CPF and methionine+cystine for sausages containing heated CPF. While tryptophan was not determined in these studies the level in pork protein generally exceeds the F A O / W H O score (Paul & Southgate, 1978) and a 30~o replacement by CPF would be unlikely to reduce the level of tryptophan to much below that of the F A O / W H O score. Biological evaluation of diets containing pork sausages with and without CPF is shown in Table 2. Protein quality measured as either N PU, BV or PER for pork sausages showed them to be of high quality comparable to that of beef(Miller & Bender, 1955; Bender & Zia, 1976).
34
M. M. Verma, R. J. Neale, D. A. Ledward TABLE I
Amino Acid Composition of Pork Sausages With and Without CPF Cooked at 150°C for 10min (g amino acid/16g N)
Amino acid
Asp Thr Se Glu Pro Gly Ala Val lleu Leu Tyr Ph
No CPF (control) 8.2 50 3.7 18.5 4.5 6.3 5.9 4.5 4.2 7.6
Lys His Arg Met + Cysteic acid
Sausage containing Heated Unheated CPF CPF 8.9 4.3 4.2 16.8 3.7 5.8 5.7 4.6 4.2 7.5
]142)
]124~"
7 1 28 63 3.8
69 26 69 3.1
FAO/WHO recommended chemical score
9.0 4.2 4.3 17.0 3.5 5.8 5.6 4.5 4.3 7.7 32 43)
4.0
5.0 4.0 7.0 6.0
6'9 27 6.4 3.5
55
3.5
TABLE 2
NPU, TD, BV, PER and Chemical Score of Pork Sausages With and Without CPF Cooked at 150°C for 10min Sausage
No CPF (control) Sausage with heated CPF Sausage with unheated CPF
NPU
TD
O (7,~)
(%)
71.0 a
960
74.0
3-1
90
73.0
94.5
77.0
3.0
89
70.0
94.7
74-0
3.0
90
a Values are means of four rats per group.
BV
PER
Chemical score
(%)
Nutritional evaluation of sausages containing chick pea flour
35
Replacement of 30 ~ of pork protein by either heated or unheated C P F had no ,;ignificant effect on protein quality measured by any of the three methods. TD tended to be slightly higher for controls than for those containing CPF, no doubt reflecting the reduced digestibility of legume proteins in general ( F A O / W H O , 1973). The chemical score calculated for the levels of essential amino acids tended to be higher than biological values. This no doubt reflects some unavailability of amino acids present in the cooked food caused possibly by effects of heating (Bender, 1978). Since no determinations of amino acid availability were however performed, it is not possible to say which amino acids were affected.
ACKNOWLEDGEMENTS We gratefully acknowledge the help of Mr D. Bozon, and Mr S. Freeman for technical assistance and the Association of Commonwealth Universities for financial assistance.
REFERENCES Bender, A. E. (1978). In: Food processing and nutrition, Academic Press, London. Bender, A. E. & Zia, M. (1976). J. Fd Technol. II, 495. FAO/WHO (1973). Wld. Health Organisation, Tech. Rep. Series No. 522. Hirs, C. H. W. (1967). In: Methods m enzymology (Colowick, S. P. & Kaplan, N. O. (Eds)) Academic Press, New York, 11, 59. Miller, D. S. & Bender, A. E. (1955). Br. J. Nutr. 9, 382. Paul, A. A. & Southgate, D. A. T. (1978). The composition of foods. HMSO. Payne, P. R. & Stewart, R. J. C. (1972). Lab. Anim. 6, 135. Verma, M. M., Ledward, D. A. & Lawrie, R. A. (1984). Meat Sci. ! I, 109.
NulLritional Evaluation of Sausages Containing Chick Pea Flour (Cicer arietinum) M. M. Verma, R. J. Neale & D. A. Ledward School of Agriculture, University of Nottingham, Sutton Bonington, Loughborough, Leics. LEI2 5RD, Great Britain (Received: 8 November, 1984)
S UMMA R Y Nutritional evaluation ojprotein quality was carried out on English-type fi'e:¢h skinless pork sausages in which 30 % of the protein had been replaced by chick pea flour, Net protein utilisation, biological value and protein efficiency ratio were unaffected by 30 % meat protein replacement. Comparison of the amino acid composition with 1he biological values suggested some reduction in amino acid availability due to cooking.
INTRODUCTION Recent work from this laboratory has investigated the feasibility of replacing meat (mutton, pork or beef) in comminuted meat products by varying levels of chick pea flour (CPF) (Cicer arietinum). Both subjective and objective criteria were employed and results showed that levels of substitution up to 30~o protein replacement could be made without adversely affecting product acceptability. Later work, however, showed that it was necessary to heat CPF to 80 °C for 1 h to prevent discoloration of raw sausages caused by lipid peroxidation on storage (Verma et al., 1984). In view of this work and the possible effects on nutritional value of the final product it was decided to investigate the influence of replacing meat by CPF on the protein quality of sausages measured by both amino acid analysis a n d / n vivo feeding trials with rats. 31
Meat Scwnce 0309-1740/85/$03.30 i~" Elsevier Applied Science Publishers Ltd, England, 1985. Printed in Great Britain
32
M. M. Verrna, R. J. Neale, D. A. Ledward
MATERIALS A N D M E T H O D S Pork sausages were prepared according to published methods (Verma et al., 1984) based on an initial composition of 9 ~o protein, 18 % fat, 56-5 % water, 15 % binder and 1.5 ~o salt. Control sausages had no C P F added. Two further samples of sausages were also prepared containing 30~, replacement of meat proteins by (a) C P F heated at 80°C for 1 h and (b) unheated CPF. All sausages were then shallow-fried at 150°C for 10min prior to chopping, freeze-drying, powdering and storage at 0 °C in moisture-proof plastic bags. The net protein utilisation (NPU) of the sausage protein was determined on rats of the Wistar strain by the method of Miller & Bender (1955) modified by grouping animals in separate cages rather than in groups of four. After weaning at 21 days the rats were fed on a basal casein diet so that they weighed between 40-45 g at the beginning of the feeding trial. The protein-free diet consisted of 150 g/kg D-glucose, 200 g/kg maize oil (including vitamins A, D, E and K), 11 g/kg vitamin B mix (Payne & Stewart, 1972), 50g/kg mineral salt mix (Payne & Stewart, 1972) and 589 g/kg maize starch. The sausage meat (containing both protein and oil) replaced part Qf the maize starch and maize oil such that each diet contained 100 g/kg total protein and 200 g/kg total fat. Rats were fed for 10 days ad libitum on all diets and at the end of the feeding period were killed with CO 2 and weighed. The carcasses were dissolved in 200 ml of 2 M NaOH by heating in a boiling water bath. The total weight of the slurry was obtained and its nitrogen content determined by the macro-Kjeldahl method. Faeces voided by the animals were collected, dried to constant weight at 105°C and milled to a fine powder with pestle and mortar, and the nitrogen content determined. N P U , true nitrogen digestibility (TD) and biological value (BV) were calculated as described (Miller & Bender, 1955). Protein efficiency ratio (PER) over 10 days was calculated as previously described. Amino acid analysis Freeze-dried cooked sausage samples (prepared as described) were left overnight at 105°C and defatted using the Soxhlet method (overnight soaking followed by 8 h continuous extraction). About 0.5 g of defatted samples were refluxed with 300ml 6M HCI for 22h in a nitrogen
Nutritional evaluation of sausages containing chick pea flour
33
atmosphere. The cooled digests were filtered and made up to 500 ml with distilled water. To 10ml of the diluted hydrolysate, l ml of 1.0M norleucine was added and the whole evaporated to dryness, under vacuum at not more than 37 °C. A few millilitres of distilled water were then added and the mixture again evaporated to dryness. The residue was dissolved in 5 ml li'Lhium citrate buffer, millipore filtered (0.2 mm) and stored at 0 °C. Cystine and cysteine were determined as cysteic acid following performic acid oxidation (Hirs, 1967). Amino acid analysis was performed using an LKB 4400 Amino Acid Analyser. Tryptophan was not determined. Calculations
BV=
NPU TD
The amino acid score was calculated by the following formula mg amino acid in test protein mg amino acid in reference protein
x
100
It is the lowest score obtained for any of the essential amino acids in the test proteins (i.e. the most limiting amino acid: FAO/WHO, 1973).
RESULTS AND DISCUSSION The amino acid composition of the sausages with and without CPF is shown in Table 1. In general all the amino acids, excepting valine and methionine and cystine (cysteic acid) are in excess of the F A O / W H O recommended score and the first limiting amino acid appears to be valine for the controls and the sausages containing the unheated CPF and methionine+cystine for sausages containing heated CPF. While tryptophan was not determined in these studies the level in pork protein generally exceeds the F A O / W H O score (Paul & Southgate, 1978) and a 30~o replacement by CPF would be unlikely to reduce the level of tryptophan to much below that of the F A O / W H O score. Biological evaluation of diets containing pork sausages with and without CPF is shown in Table 2. Protein quality measured as either N PU, BV or PER for pork sausages showed them to be of high quality comparable to that of beef(Miller & Bender, 1955; Bender & Zia, 1976).
34
M. M. Verma, R. J. Neale, D. A. Ledward TABLE I
Amino Acid Composition of Pork Sausages With and Without CPF Cooked at 150°C for 10min (g amino acid/16g N)
Amino acid
Asp Thr Se Glu Pro Gly Ala Val lleu Leu Tyr Ph
No CPF (control) 8.2 50 3.7 18.5 4.5 6.3 5.9 4.5 4.2 7.6
Lys His Arg Met + Cysteic acid
Sausage containing Heated Unheated CPF CPF 8.9 4.3 4.2 16.8 3.7 5.8 5.7 4.6 4.2 7.5
]142)
]124~"
7 1 28 63 3.8
69 26 69 3.1
FAO/WHO recommended chemical score
9.0 4.2 4.3 17.0 3.5 5.8 5.6 4.5 4.3 7.7 32 43)
4.0
5.0 4.0 7.0 6.0
6'9 27 6.4 3.5
55
3.5
TABLE 2
NPU, TD, BV, PER and Chemical Score of Pork Sausages With and Without CPF Cooked at 150°C for 10min Sausage
No CPF (control) Sausage with heated CPF Sausage with unheated CPF
NPU
TD
O (7,~)
(%)
71.0 a
960
74.0
3-1
90
73.0
94.5
77.0
3.0
89
70.0
94.7
74-0
3.0
90
a Values are means of four rats per group.
BV
PER
Chemical score
(%)
Nutritional evaluation of sausages containing chick pea flour
35
Replacement of 30 ~ of pork protein by either heated or unheated C P F had no ,;ignificant effect on protein quality measured by any of the three methods. TD tended to be slightly higher for controls than for those containing CPF, no doubt reflecting the reduced digestibility of legume proteins in general ( F A O / W H O , 1973). The chemical score calculated for the levels of essential amino acids tended to be higher than biological values. This no doubt reflects some unavailability of amino acids present in the cooked food caused possibly by effects of heating (Bender, 1978). Since no determinations of amino acid availability were however performed, it is not possible to say which amino acids were affected.
ACKNOWLEDGEMENTS We gratefully acknowledge the help of Mr D. Bozon, and Mr S. Freeman for technical assistance and the Association of Commonwealth Universities for financial assistance.
REFERENCES Bender, A. E. (1978). In: Food processing and nutrition, Academic Press, London. Bender, A. E. & Zia, M. (1976). J. Fd Technol. II, 495. FAO/WHO (1973). Wld. Health Organisation, Tech. Rep. Series No. 522. Hirs, C. H. W. (1967). In: Methods m enzymology (Colowick, S. P. & Kaplan, N. O. (Eds)) Academic Press, New York, 11, 59. Miller, D. S. & Bender, A. E. (1955). Br. J. Nutr. 9, 382. Paul, A. A. & Southgate, D. A. T. (1978). The composition of foods. HMSO. Payne, P. R. & Stewart, R. J. C. (1972). Lab. Anim. 6, 135. Verma, M. M., Ledward, D. A. & Lawrie, R. A. (1984). Meat Sci. ! I, 109.