• Asian-Australasian Journal of Animal Sciences
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• v.8 no.5
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• pp.433-441
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• 1995

A series of experiments was conducted to determine the influence of various pepsin-HCL pretreatment factor, hereby the factors of duration of washing for the retrieved bags, inherent to the mobile nylon bag technique (MNBT), on apparent ileal digestibility of crude protein (AIDCP) and apparent ileal digestibility of dry matter (AIDDM). At last, the AIDCP and apparent ileal digestibility of amino acids (AIDAA) in maize, barley, wheat, rapeseed meal, cottonseed meal and three mixed diets were determined with the MNBT and ileo-rectal anastomis pigs (IRAT). For the MNBT techniques, bag measuring $25{\times}40$ MM and containing 0.75 g feedstuff samples, after pre-digestion in vitro, were introduced into the ileo-rectal anastomis pigs (IRAT) gastrointestinal tract through a duodenal cannula and recovered in the ileal digesta between 6 and 12 h. later. 1. The apparent ileal digestibility of dry matter (AIDDM) and crude protein (AIDCP) of the tested samples, with the exception of fish meal, determined by MNBT were not affected by the different pepsin-HCL pretreatment times in vitro between 2.5 h. and 4 h. 2. There was no significant (p > 0.05) difference of the AIDCP and AIDDM of maize determined by the MNBT among different pepsin concentration (0.03%, 0.07% and 0.1 %) treatment in vitro. 3. The AIDCP determined with the MNBT was affected by the washed and unwashed recovered bags from the ileal digesta. 4. The AIDCP and AID amino acids (AIDAA) of maize, barley, wheat, rapeseed meal, soya-bean meal, cottonseed meal and three mixed diets from the MNBT, with a solution of 0.01N HCL (PH 2) and 0.1% of pepsin concentration, a pepsin-HCL pretreatment time in vitro or 4h. and a washing time of the recovered bag from the ileal digesta compared well with those from the IRAT. The linear regression analysis showed a significant correlation (p < 0.01) of AIDCP and AIDDA between the IRAT and MNBT.

• Journal of Animal Environmental Science
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• v.11 no.2
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• pp.125-134
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• 2005

This study was conducted to evaluate changes of microbial population, pepsin digestibility of protein and in vitro digestibility of nutrients of food waste mixture pasteurized and cured using a rotary drum system. A pasteurization process (30 min at $80^{\circ}C$) tended to decrease microbial populations and eliminated (P<0.05) molds in food waste mixture. The subsequent curing process increased (P<0.05) lactic acid bacteria counts which were reduced by the heated pasteurization process. The heated pasteurization process decreased (P<0.05) pepsin digestibility of protein in food waste mixture. In vitro digestibilities of dry matter and organic matter were high in the order of bakery by-product, wheat bran, food waste (=barley bran). These results indicate that food waste mixture pasteurized and cured using a semi-dehydration rotary drum system may be an effective animal feed resource.

• Journal of Nutrition and Health
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• v.28 no.10
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• pp.986-994
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• 1995

This study was to examine the effect of phytate on the protein digestibility and calcium, iron and zinc availability in phytase treated soymilks digested with pepsin and pepsin-pancreatin in vitro. Also, the bending between phytate and protein in soymilks was investigated by means of SDS-PAGE. The content of phytate in soymilk was reduced by phytase treatment. As the content of phytate decreased, the protein digestibility increased in soymilk treated with the digest enzymes in vitro. The reduction of phytate content in soymilk improved the availability of all calcium, iron and zinc. Although the availability of calcium increased, the amount of change was small. The phytate reduction increased most the availability of iron. A number of bands of high molecular weight protein in soymilk disappleared in SDS-PAGE by lowering the phytate content with phytase treatement on soymilk.

• Journal of Nutrition and Health
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• v.10 no.2
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• pp.27-34
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• 1977

The present study was carried out to evaluate the nutritional quality of rabbit meat protein. The composition of amino acids contained in rabbit meat was compared with those of other animal meats such as beef, pork and chicken. Also included in this study was the question whether the cooking and storage conditions affect the amino acid composition and the pepsindigestibility of rabbit meat protein. The results are summarized as follows: 1. The large variation observed from sample to sample of EAA (essential amino acid) composition in rabbit meat was found to be an interesting but peculiar property of rabbit meat protein. The most limiting amino acid of rabbit meat protein was phenylalanine, whereas methionine was the first limiting amino acid of both beef and pork proteins. Chemical scores of various meat proteins were 68, 65, 66, and 74 for rabbit meat, beef, pork, and chicken respectively. 2. In pan roasting, the EAA damaged most by heat was methionine (15%). When cooked after two months of frozen storage, lysine decreased most. 3. Higher pepsin digestibility was obtained by cooking rabbit meat after seasoned in alcohol, ginger juice, and other spices compared with various other cooking conditions without seasoning. The pepsin digestibility value was even higher for the seasoned meat than for the raw meat. 4. Among various meats tested the rabbit meat showed the lowest pepsin digestibility. 5. A simple measurement of released methionine could be used to determine relative digestibility instead of measuring $NH_2-N$ content after pepsin digestion. From all the results obtained in this study it can be concluded that rabbit meat is a good Protein food item when used fresh and stored properly to prevent rancidity problems. It is suggested to study further the peroxidation effect of unsaturated fatty acids on protein quality. This study was supported by the Ministry of Science and Technology in Korea.

• Asian-Australasian Journal of Animal Sciences
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• v.17 no.3
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• pp.379-385
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• 2004

Two trials in vivo and in vitro were conducted, in vivo to determine the apparent digestibility of gross energy, crude protein, dry matter, acid detergent fiber, neutral detergent fiber and apparent digestible energy in 10 corn by-products. In vivo the diets included one basal corn diet, four corn gluten meal diets, four corn distillers dried grains with solubles diets and two corn distillers dried grains diets using the different methods, 12 crossbred barrows weigh $40{\pm}$1.6 kg were allocated into individual metabolic crate, according to a $6{\times}6$ Latin square design. In vitro using flask technique, filter bag technique and dialysis tubing technique, the digestibilities of gross energy, crude protein and dry matter in corn gluten meal and corn distillers dried grains with solubles were investigated. Pepsin, pancreatin, intestinal fluid, rumen fluid and cellulase were used in incubation. The results showed that correlation coefficient was 0.73 in corn distillers dried grains with solubles between the digestibility of crude protein and acid detergent fiber in vivo (p<0.01); and correlation coefficient was 0.68 in corn distillers dried grains with solubles between the digestibility of gross energy and neutral detergent fiber in vivo (p<0.01). Apparent digestible energy (DE) of corn by-products in pig total tract was predicted by the percentage of crude protein (CP) and the content of gross energy (GE) in feedstuff. The equation: DE=5,601.09+26.69$\times$CP %-0.5904$\times$GE, ($R^2=0.72$). In vitro, filter bag technique was more convenient; furthermore, the digestibility for the treatments (pepsin+pancreatin+rumen fluid and pepsin+pancreatin+cellulase) was better.

• Korean Journal of Food Science and Technology
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• v.26 no.5
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• pp.603-608
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• 1994

This study was undertaken to find out the effect of phytate on the protein digestibility of various soybean foods, including soy milk, bean curd, curd residue, cheongkukjang, soy sauce, and soy paste. The phytate content of soybean was 2.4%, which decreased to 0.2%, 0.7%, and 0.4% in soy milk, bean curd, and curd residue, respectively, and to 0.2% and 1.0% in soy sauce and soy paste, respectively. The phytate/protein ratio was not correlated with protein digestibility by pepsin whereas the ratio was highly correlated with pancreatin digestibility (p<0.01, r= -0.73). According to SDS-PAGE for the soluble protein fractions, soaked bean showed an alteration in soluble components and bean curd residue exihibited newer low molecular weight bands. Fermented soy products showed no protein band, likely due to degradation.

• Korean Journal of Soil Science and Fertilizer
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• v.38 no.5
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• pp.253-258
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• 2005

It is necessary to determine a nitrogen supplying capacity (NSC) of soil for sustainable agriculture. NSC has been decided by directly detecting N mineralization potential (NMP) and inorganic nitrogen or by indirectly approximating from organic matter and chemical properties of soil. NMP is best method for NSC but it takes long period. A study was conducted to find a short-term incubation method using pepsin through 1) determining NMP of 3 upland and 3 paddy soils, 2) establishing analytical condition of pepsin digestion by comparing to NMP, 3) validating with relations to N requirements for maximum yield of rice. NMPs of 6 soils were ranges from $63mg\;N\;kg^{-1}$ to $156mg\;N\;kg^{-1}$. The pepsin digestion method of soil nitrogen was established by determining amino nitrogen from digesting 5 g of soil for 30 minutes by 0.02% pepsin. This method was so highly correlated with a maximum rate of nitrogen fertilizer that it could be used for determining NSC in paddy soil.

• Asian-Australasian Journal of Animal Sciences
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• v.15 no.10
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• pp.1507-1516
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• 2002

Meat and bone meal is a valuable protein and mineral source in diets of production animals and contributes to the protein, energy and mineral component of diets. The aim of the present study was to more accurately characterise the apparent ileal amino acid digestibility of meat and bone meals produced in New Zealand and evaluate routine in vitro assays used in practise to measure meat and bone meal quality. A total of 94 commercial meat and bone meals from 25 New Zealand rendering plants over a two and a half year period were analysed for proximates, gross energy, gross amino acid content (incl. hydroxyproline, hydroxylysine and lanthionine), apparent ileal amino acid digestibility, pepsin nitrogen digestibility, protein solubility and bone content. The mean crude protein content of the 94 meat and bone meal samples was 56.8% with a range of >35% units and a coefficient of variation of 9.8%. The mean crude fat and ash content were 10.0 and 28.4% respectively. These latter components showed a large range (16 and 43%, respectively) with coefficients of variation above 22%. Amino acid digestibility between samples was highly variable with lysine and sulphur amino acids digestibility ranging between 45.8-89.0 and 38.2-85.5%, respectively. Pearson correlation coefficients are presented between crude protein content and individual gross amino acids, crude protein content and individual digestible amino acid content, and pepsin N digestibility and individual digestible amino acid content. There was a significant relationship between the digestible amino acid nitrogen content and the crude protein content while pepsin nitrogen digestibility was not correlated to ileal amino acid nitrogen digestibility (r=-0.06). Meat meals with a high protein content had relatively low hydroxyproline and hydroxylysine levels something that was attributed to the levels of collagen from bone. The data indicated that lanthionine (formed upon heat treatment of cysteine with a hydroprotein) is not a good indicator of the heat treatment employed to meat and bone meals. Step-wise multiple regression equations to predict the apparent digestible content of amino acids from rapid in vitro assays are presented. The most selected variables included ash and crude fat content. In general the equations derived for the essential amino acids had a higher degrees of fit (R2) compared to the non-essential amino acids. The R2 for the essential amino acids ranged from 0.43 for histidine and 0.68 for leucine. These equations provide a means of more rapidly estimating the apparent ileal digestible amino acid content (protein quality) of meat and bone meal using standard analyses.

• Korean Journal of Poultry Science
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• v.11 no.1
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• pp.13-17
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• 1984

Protein digestibitlities of hydrolyzed cattle skin meals were examined at a constant pepsin-MC$\ell$ concentration (0.2%) for varying lengths of incubation time (from 4 to 20 hours) and at varying concentrations of pepsin-HC$\ell$ (from 0.0125 to 0.2%) for 16 hours at 45$^{\circ}C$. The results are summarized as follows: 1. Protein digestibilities of hydrolyzed cattle skin meals in 0.2% pepsin-HCl were 66.31%, 80.69%, 83.72%, 84.65% and 81.45% for 4, 8, 12, 16 and 20 hours incubation, respectively. Protein digestibilities were maintained above 80% for 8-hour incubation and were increasing incubation time. 2. Protein digestibilities of hydrolyzed cattle skin meal incubated for 16 hours at 0.2%, 0.1%, 0.05%, 0.025% and 0.0125% pepsin-HC$\ell$ solution were 85.10%, 82.08%, 76.18%, 74.67% and 64.82%, respectively. Protein digestibilities were decreased with decreasing pepsin concentration.

• Korean Journal of Food Science and Technology
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• v.6 no.2
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• pp.70-74
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• 1974

The round muscle of Korean cattle and squid muscle were cooked with various methods which were followed digestibility test by use of pepsin in-vitro, determination of amino nitrogen in the course of digestion procedure by using Formol method (AOAC) and influence of ether treatment for preminary test also examined. The results obtained were summarized as follows: 1. The order of digestibility values were demonstrated as follows: In case of beef, it was autoclaving, frying, raw, freezing, roasting, boiling and in case of squid muscle, it was raw, autoclaving, boiling, freezing, dry heating and roasting. 2. The amounts of amino nitrogen for beef and squid muscle were increased in proportion to digestibility value. 3. There were no significances in the digestibility between treating with ether and none of any treatment of beef and squid muscle in raw condition.