In Vitro Measurement of Effects of Processing on Protein Nutritional Quality1

1982 ◽  
Vol 45 (13) ◽  
pp. 1248-1256 ◽  
Author(s):  
HAROLD E. SWAISGOOD ◽  
GEORGE L. CATIGNANI
Keyword(s):  
Amino Acid ◽  
Acid Hydrolysis ◽  
Protein Digestibility ◽  
In Vitro Assays ◽  
Processing Conditions ◽  
Fluorometric Method ◽  
Chemical Methods ◽  
Chemical Score ◽  
Available Lysine

Effects of processing on protein structure and its nutritional consequences, and progress towards development of more rapid in vitro assays of nutritional quality are reviewed. Heat and/or alkali processing of proteins initiates Maillard and carbonylamine reactions, causes β-elimination of cystinyl and substituted seryl and threonyl residues, and causes racemization of certain residues. Depending on the extent of these reactions, as determined by the severity of processing conditions, resulting changes may adversely affect bioavailability. Chemical methods for assaying quality have been developed such as the “Chemical Score,” which is based on amino acid analysis of acid hydrolysates, and methods for determining available lysine by reaction with FDNB. Recently a more rapid fluorometric method for measuring available lysine based on reaction with o-phthalaldehyde and mercaptoethanol was developed. Progress is also being made toward improvement of amino acid scores by replacing acid hydrolysis with total enzymic hydrolysis, which should be sensitive to chemical modifications of residues that are eliminated by acid hydrolysis. Reactors containing combinations of immobilized proteinases and peptidases are being characterized for this purpose. Some improvement of amino acid scores is also afforded by adjustments for protein digestibility. Studies of model digestive systems composed of immobilized gastric, pancreatic and intestinal mucosal proteinases and peptidases indicate that such systems may provide parameters reflecting bioavailability.

Chemical and Nutritional Evaluation of Pumpkin (Cucurbita pepo) Seed Proteins

2019 ◽  
pp. 1-11 ◽  
Author(s):  
Adanma C. Innocent-Ukachi
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Chemical Properties ◽  
Seed Proteins ◽  
Protein Digestibility ◽  
Amino Acid Profile ◽  
Protein Isolate ◽  
Pumpkin Seed ◽  
Chemical Score

Chemical and nutritional properties of pumpkin (Curcubita pepo) seed proteins were studied. The seed was processed into defatted flour (CPF) which was further processed into Curcubita protein concentrate (CPC) and Curcubita protein isolate (CPI) by alkaline water/isoelectric precipitation. Chemical properties of the protein products were determined using standard methods of analysis. The amino acid profile was determined by an automated Technicon® liquid chromatography system. Protein digestibility was assessed in-vitro (IVPD) using trypsin-pepsin enzyme method while biological values were determined on the basis of their amino acid profile. Protein efficiency ratio (PER) was estimated according to a standard proposed regression equation. The seed proteins demonstrated high levels of crude protein (CPC=69.98% and CPI=74.15%), vitamin C (CPC=43.46 and CPI=52.36 mg/ml) and vitamin A (CPC=100.56 and CPI= 63.43 I.U/g) with low levels of thiamin and riboflavin. Both proteins showed low and similar (p>0.05) levels of sodium (0.14-0.18%), calcium (0.86-1.02%), magnesium (0.53-0.58%) and phosphorus (0.09-0.11%). Percentage ratios of essential to total amino acids obtained for CPC and CPI (44.24% and 45.50%, respectively) were greater than 36% which is considered adequate for an ideal protein. Protein biological values obtained for CPC and CPI respectively were: 95% and 53% (chemical score), 2.80 and 1.56 (PER} and 70.10% and 51.28% (essential amino acid index). CPC showed a better digestibility than CPI with IVPD value of 56.88%. Threonine and lysine were the most limiting amino acids in both protein products. All anti-nutrients evaluated were low and below allowable limits. In conclusion pumpkin seed proteins showed good biological values and could be used to improve the quality of other plant proteins or as a possible replacement for animal proteins in conventional foods.

Extent of damage to amino acid availability of whey protein heated with sugar

1991 ◽  
Vol 58 (4) ◽  
pp. 431-441 ◽  
Author(s):  
Thérèse Desrosiers ◽  
Laurent Savoie
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Whey Protein ◽  
Significant Proportion ◽  
Protein Digestibility ◽  
Heating Time ◽  
Heat Treatments ◽  
Molar Ratio ◽  
Amino Acid Availability

SummaryThe effect of heat treatments, at various water activities (αw), on digestibility and on the availabilities of amino acids of whey protein samples in the presence of lactose was estimated by an in vitro digestion method with continuons dialysis. Four αw (0·3, 0·5, 0·7 and 0·97), three temperatures (75, 100 and 121 °C) and three heating periods (50, 500 and 5000 s) were selected. The initial lysine: lactose molar ratio was 1:1. Amino acid profiles showed that excessive heating of whey (121 °C, 5000 s) destroyed a significant proportion of cystine at all αw, lysine at αw 0·3, 0·5 and 0·7, and arginine at αw 0·5 and 0·7. At αw 0·3, 0·5 and 0·7, protein digestibility decreased (P < 0·05) as the temperature increased from 75 to 121 °C for a heating period of 5000 s, and as the heating time was prolonged from 500 to 5000 s at 121 °C. Excessive heating also decreased (P < 0·05) the availabilities of ail amino acids at αw 0·3, 0·5 and 0·7. The availabilities of lysine, proline, aspartic acid, glutamic acid, threonine, alanine, glycine and serine were particularly affected. Severe heating at αw 0·97 did not seem to favour the Maillard reaction, but the availabilities of cystine, tyrosine and arginine were decreased, probably as a result of structural modifications of the protein upon heating. Heating whey protein concentrates in the presence of lactose not only affected lysine, but also impaired enzymic liberation of other amino acids, according to the severity of heat treatments and αw.

scholarly journals Energy values and protein digestibility of soybean milk by-product in pigs based on in vitro assays

2020 ◽  
Vol 34 (1) ◽  
pp. 73-81
Author(s):  
Jung Yeol Sung ◽  
Bokyung Hong ◽  
Youngeun Song ◽  
Beob Gyun Kim
Keyword(s):  
Protein Content ◽  
Crude Protein ◽  
Protein Digestibility ◽  
Metabolizable Energy ◽  
In Vitro Assays ◽  
Feed Ingredient ◽  
Soybean Milk ◽  
Gross Energy ◽  
Swine Diets

Background: Soybean milk by-product (SMBP) is a potential alternative feed ingredient in swine diets due to its high protein content. However, information on energy and nutritional values of SMBP used as swine feed ingredient is limited. Objective: To estimate energy values and protein digestibility of SMBP in pigs based on in vitro assays. Methods: Four SMBP samples were obtained from 3 soybean milk-producing facilities. In vitro total tract disappearance (IVTTD) and in vitro ileal disappearance (IVID) of dry matter (DM) in the SMBP samples were determined. In vitro ileal disappearance of crude protein was determined by analyzing crude protein content in undigested residues after determining IVID of DM. Digestible and metabolizable energy of SMBP were estimated using gross energy, IVTTD of DM, and prediction equations. Results: Sample 4 had greater IVTTD of DM than that of sample 3 (97.7 vs. 94.4%, p<0.05), whereas IVID of DM in sample 4 was lower compared with sample 1 (53.5 vs. 65.0%, p<0.05). In vitro ileal disappearance of crude protein in sample 2 was greater than that in sample 1 and 3 (92.6 vs. 90.6 and 90.1%; p<0.05). The estimated metabolizable energy of SMBP ranged from 4,311 to 4,619 kcal/kg as-is basis and the value of sample 3 was the least (p<0.05) among SMBP samples. Conclusion: Energy values and protein digestibility should be determined before using SMBP in swine diets.

In vitro assays predicts mineral retention and apparent protein digestibility of different fish feed measured using a juvenileP. mesopotamicusmodel

2018 ◽  
Vol 49 (6) ◽  
pp. 2267-2277 ◽  
Author(s):  
Raúl E Cian ◽  
Carla Bacchetta ◽  
Jimena Cazenave ◽  
Silvina R Drago
Keyword(s):  
Protein Digestibility ◽  
In Vitro Assays ◽  
Fish Feed

In Vitro Assay for Predicting Protein Efficiency Ratio as Measured by Rat Bioassay: Collaborative Study

1982 ◽  
Vol 65 (4) ◽  
pp. 798-809 ◽  
Author(s):  
Lowell D Satterlee ◽  
James G Kendrick ◽  
Henry F Marshall ◽  
Duane K Jewell ◽  
Rida A Ali ◽  
...  
Keyword(s):  
Amino Acid ◽  
Protein Efficiency Ratio ◽  
Muscle Protein ◽  
Collaborative Study ◽  
Protein Digestibility ◽  
Efficiency Ratio ◽  
Breakfast Cereal ◽  
Vitro Assay ◽  
Food Ingredients

Abstract Seven laboratories collaborated in testing the calculated protein efficiency ratio (C-PER and DC-PER). The collaborative study required each laboratory to analyze 6 foods and a control protein (ANRC casein) for in vitro apparent protein digestibility, amino acid composition, and PER via rat bioassay. The 6 foods or food ingredients tested were nonfat dry milk, cooked chicken muscle, protein-fortified dry breakfast cereal, textured soy protein, oat-based dry breakfast cereal, and durum wheat flour. Data obtained from the study were analyzed statistically for the intralaboratory variation for each method of analysis (i.e., amino acid analysis, PER, etc.). The ability of the C-PER to rapidly predict rat PER was also measured. The C-PER and DC-PER methods were adopted official first action.

scholarly journals In vitro techniques for the assessment of the nutritive value of feed grains for pigs: a review

1999 ◽  
Vol 50 (5) ◽  
pp. 871 ◽  
Author(s):  
Paul J. Moughan
Keyword(s):  
Nutritive Value ◽  
Protein Digestibility ◽  
In Vitro Assays ◽  
In Vitro Digestibility ◽  
In Vitro Techniques ◽  
Ileal Digestibility ◽  
Plant Fibre ◽  
Gross Energy

The philosophy inherent in developing in vitro digestibility assays for dietary energy and protein is reviewed and an historical account is given of the development of such assays for the pig. General principles to be considered in the development of in vitro digestibility assays are discussed, as are limitations of the in vitro approach. The importance of choosing the most appropriate in vivo measures of digestibility for the evaluation of in vitro assays is stressed. For protein sources that do not contain anti-nutritional factors or plant fibre, ‘true’ ileal digestibility should be the in vivo baseline, while plant proteins should be tested against ‘real’ ileal digestibility. There is a dearth of adequately conducted validation studies for in vitro digestibility assays. It appears that the 3-step (pepsin, pancreatin, Viscozyme) closed in vitro system to allow prediction of organic matter and gross energy digestibility in the pig has particular promise for practical feed evaluation. Similarly based protein digestibility assays may require further development before they can be applied with confidence.

scholarly journals Nutritional availability of methionine, lysine and tryptophan in fish meals, as assessed with biological, microbiological and dye-binding assay procedures

1985 ◽  
Vol 53 (3) ◽  
pp. 575-586 ◽  
Author(s):  
D. Hewitt ◽  
J. E. Ford
Keyword(s):  
Amino Acid ◽  
Tetrahymena Pyriformis ◽  
Poor Quality ◽  
Analysis Procedure ◽  
Chick Growth ◽  
Vitro Assay ◽  
Similar Treatment ◽  
Dye Binding ◽  
Available Lysine

1. In vitro assay procedures were applied in the measurement of available amino acids in a selection of fish meals representing good- and poor-quality product. Results were assessed by comparing them with results from chick-growth assays.2. Available methionine and tryptophan were assayed microbiologically with Streptococcus zymogenes, after predigestion of the test samples with papain or pronase. Results for methionine were correlated with chick-growth assays (r 0.86 for papain, 0.91 for pronase; P < 0.01). Compared with the chick assays, papain tended to give lower, and pronase higher, results. Finer milling of the test samples did not influence the pronase values.3. Results for available tryptophan were also correlated with chick-growth assays (r 0.95 for papain, 0.96 for pronase; P < 0.001). Compared with the chick values, papain gave markedly lower results and pronasem marginally higher ones. Finer milling of the test samples increased the papain values by about 50% but had no effect with pronase.4. Available lysine was assayed microbiologically with Tetrahymena pyriformis and with a dye-binding procedure (DBL). The results correlated with the chick-growth assays (r 0.99 for DBL, P < 0.001; 0.85 for Tetrahymena, P < 0.01) but both methods overrated the poorer-quality samples.5. True nitrogen digestibilities and amino acid digestibilities were determined with chickens by the 'ileal analysis' procedure: the amino acid digestibilities were significantly higher and similar to the corresponding availabilities as measured in chick-growth assays.6. Ball milling a poor-quality fish meal caused a marked fall in its N digestibility, whereas similar treatment of a good-quality meal caused a slight increase. An explanation for this finding is proposed.7. Strep. zymogenes assays following pronase digestion of the test samples gave precise and acceptably accurate measures of the biologically available methionine and tryptophan in the test samples. For available lysine, Tetrahymena and DBL values for the poorer-quality samples were notably higher than the chick-growth assay; possible reasons for this are discussed. The ileal analysis procedure underestimated true N digestibility.

scholarly journals Amino Acid Profile/Score and In-vitro Protein Digestibility of Biscuits Produced from Wheat Flour, African Breadfruit Flour and Moringa Seed Flour Blends

2020 ◽  
pp. 34-42
Author(s):  
V. C. Wabali ◽  
S. Y. Giami ◽  
D. B. Kiin- Kabari ◽  
O. M. Akusu
Keyword(s):  
Amino Acid ◽  
Wheat Flour ◽  
Protein Digestibility ◽  
Amino Acid Profile ◽  
In Vitro Protein Digestibility ◽  
Seed Flour ◽  
African Breadfruit ◽  
Profile Score ◽  
Vitro Protein

The objective of this work was to evaluate the Amino Acid profile/score and In-vitro protein digestibility of composite biscuits produced from blends of Wheat flour (WHF), African breadfruit flour (ABF)and Moringa seed flour(MSF) at the following ratios (Sample A: WHF 100%: ABF 0; MSF 0, B= WHF 77.5%:ABF 20%: MSF 2.5%, C=WHF 75%: ABF 20%: MSF 5.0%, D= WHF 72.5%: ABF 20%: MSF 7.5%. E = WHF 70%: ABF 20%: MSF 10%, F = WHF 90%: ABF 0: MSF 10%, G = WHF 80%: ABF 20%: MSF 0). The most predominant Amino Acid in ABF was glutamic (12.27 g/100 g) followed by Aspartic and lysine, with values of 8.96 g/100 g and 6.55 g/100 g, respectively. Glutamic Acid content of the biscuits ranged from 10.96 g/100 g – 12.96 g/100 g, with sample B giving significantly higher value. Substitution with MSF resulted in decreasing glutamic acid content levels in the formulated biscuits, while lysine, phenylalanine and Isoleucine improved with the addition of 10% Moringa seed flour. Amino acid Scores of the biscuits using Hen egg as standard showed that whole egg had a higher amino acid score except glycine (1.04 – 1.25). Percentage In-vitro protein digestibility ranged from 10.64% - 47.33%, showing that addition of moringa seed flour and African breadfruit flour improved digestibility values from 10.64% to 47.33% for sample E with the control sample (wheat flour biscuit) being significantly lower. Substitution with ABF and MSF improved protein digestibility of the produced biscuits. Also, the Amino acid scores of the formulated biscuits were higher than the FAO recommended daily dietary requirements for Amino acids.

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