• Mass Spectrometry Letters
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• v.2 no.4
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• pp.84-87
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• 2011

The effectiveness of microwave-assisted protein digestion in different well positions of a 96-well microplate was investigated where microwave-assisted protein digestion of bovine serum albumin was performed in 10 different wells of a 96-well microplate in a microwave oven. Similarly increased sequence coverages (~70%) were generally observed for the 10 microwave-assisted protein digestion samples compared to conventional overnight digestion (63%), which is possibly due to higher miscleavage ratios (~53%) of the samples from microwave-assisted protein digestion than conventional overnight digestion (42.1%). The reproducible results of microwave-assisted digestions from different well positions demonstrate the potential of high-throughput analysis of proteins using microwave-assisted protein digestion.

• Journal of Animal Science and Technology
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• v.65 no.1
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• pp.32-56
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• 2023

This review explores the factors that improve meat protein digestibility and applies the findings to the development of home meal replacements with improved protein digestion rates in older adults. Various methods improve the digestion rate of proteins, such as heat, ultrasound, high pressure, or pulse electric field. In addition, probiotics aid in protein digestion by improving the function of digestive organs and secreting enzymes. Plant-derived proteases, such as papain, bromelain, ficin, actinidin, or zingibain, can also improve the protein digestion rate; however, the digestion rate is dependent on the plant enzyme used and protein characteristics. Sous vide processing improves the rate and extent of protein digestibility, but the protein digestion rate decreases with increasing temperature and heating time. Ultrasound, high pressure, or pulsed electric field treatments degrade the protein structure and increase the proteolytic enzyme contact area to improve the protein digestion rate.

• Analytical Science and Technology
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• v.30 no.2
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• pp.96-101
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• 2017

This study investigated the effect of centrifugation on tryptic digestion. This was done by applying different centrifugation speeds (6,000, 8,000, 10,000, 20,000, and $30,000{\times}g$) over various durations (0, 10, 20, 30, 40, 50, and 60 min) to digest two model proteins - cytochrome c and myoglobin. The intact proteins and resulting peptides were identified using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. Centrifugation greatly improved the tryptic digestion efficiency of cytochrome c, where either an increase in centrifugation speed or in digestion duration significantly improved the digestion of cytochrome c. However, centrifugation did not noticeably improve the digestion of myoglobin; 16 h of centrifuge-assisted tryptic digestion at $30,000{\times}g$ barely removed the myoglobin protein peak. Similar results were also obtained when using conventional tryptic digestion with gentle mixing. When acetonitrile (ACN) was added to make 10% ACN buffer solutions, the myoglobin protein peak disappeared after 6 h of digestion using both centrifuge-assisted and conventional tryptic digestions.

• Asian-Australasian Journal of Animal Sciences
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• v.14 no.10
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• pp.1374-1382
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• 2001

Fifteen Inner Mongolian wethers with permanent ruminal and duodenal cannulas were used to study the effects of dietary rumen-undegradable protein (RUP) to rumen-degradable protein (RDP) ratios or protein sources on fiber digestion in the gastrointestinal tract and ruminal fluid characteristics. Fiber digestion and ruminal fermentation were not affected (p>0.05) by dietary RUP to RDP ratios (from 1.54 to 0.72). Soybean meal supplementation improved ruminal digestion. Fish meal supplementation increased (p<0.05) the ruminal degradability of fiber. The different RUP to RDP ratios (from 1.54 to 0.72) did not influence (p>0.05) ruminal fluid pH, but there were differences (p<0.05) in ruminal fluid $NH_3-N$ concentration because of urea replacement. Soybean meal as a dietary protein source decreased (p<0.05) ruminal fluid pH and increased (p<0.05 or p<0.01) $NH_3-N$, acetate, propionate and butyrate concentrations in the rumen. Fish meal as a dietary protein source decreased (p<0.05 or p<0.01) ruminal $NH_3-N$ and acetate concentrations and increased (p<0.05) ruminal propionate concentration. It can be concluded that dietary protein sources have more significant effect on fiber digestion and ruminal fermentation than different dietary RUP to RDP ratios, when the dietary crude protein requirements of growing sheep are satisfied.

• Asian-Australasian Journal of Animal Sciences
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• v.13 no.3
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• pp.317-322
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• 2000

In situ and in vivo digestion trials were conducted to determine the degradation of dry matter (DM), crude protein (CP) and effective protein degtadability (EPD), and digestibility of nutrients of Hazelnut kernel oil meal (HKOM), and effects of HKOM on nitrogen (N) balance. In the in situ study, nylon bag were suspended in the rumen of 3 Karayaka rams to estimate protected protein. Protein sources were analyzed for pepsin soluble protein (PSP) using a Pepsin Digestion Method. In the digestion trials, 4 Karayaka rams (36 mo.) were used in a $4{\times}4$ Latin square to evaluate the digestibility of nutrients and N retention to measure effects of diets containing HKOM, soybean meal (SBM) corn gluten meal (CGM) and urea (U). The degradability of DM and CP, and PSP content of HKOM were lower (p>0.05) than that of SBM, but higher (p<0.001) than that of CGM. EPD of HKOM was higher (p<0.01) than that of SBM or CGM. The apparent digestion coefficients of organic matter and CP for HKOM were lower than for SBM, but higher than for CGM. N retention of HKOM was higher than that of SBM and lower than that of CGM (p>0.05). In conclusion, these data may indicate that the HKOM is a high digestible feed source with a value between SBM and CGM.

• Food Science of Animal Resources
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• v.39 no.6
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• pp.1000-1007
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• 2019

This study investigated protein digestibility of beef puree in infant and adult in vitro digestion models. The simulated digestive juices for infant and adult were prepared. Protein digestibility of beef puree was calculated in the gastric and gastrointestinal compartments. The 10% trichloroacetic acid soluble nitrogen and α-amino group contents of gastric digesta were lower in the infant in vitro digestion model than those in the adult in vitro digestion model (p<0.05). In addition, the gastrointestinal digesta from the infant in vitro digestion model had lower value of the 10% trichloroacetic acid soluble nitrogen and α-amino group contents than those of the adult in vitro digestion model (p<0.05). The results of sodium dodecyl sulfate-polyacrylamide gel electrophoresis showed that the remarkable bands of actin and myosin light chain B were found in the digesta of beef puree from the infant in vitro digestion model. The results of this study revealed the lower protein digestibility of beef puree in infants compared to that in adults. Therefore, the development of ways to increase digestibility of meat protein can improve the nutritional quality of meat products for infants.

• Bulletin of the Korean Chemical Society
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• v.32 no.2
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• pp.599-604
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• 2011

In typical proteomic analysis, trypsin digestion is one of the most time-consuming steps. Conventional proteomic sample preparation methods use an overnight trypsin digestion method. In this study, we compared high-pressure cycling technology (PCT) during enzyme digestion for proteome analysis to the conventional method. We examined the effect of PCT on enzyme activity at temperatures of 25, 37, and $50^{\circ}C$. Although a fast digestion (1 h) was used for the standard protein mixture analysis, the PCT-assisted method with urea showed better results for protein sequence coverage and the number of peptides identified compared with the conventional method. There was no significant difference between temperatures for PCT-assisted digestion; however, we selected PCT-assisted digestion with urea at $25^{\circ}C$ as an optimized method for fast enzyme digestion, based on peptide carbamylation at these conditions. The optimized method was used for stem cell proteome analysis. We identified 233, 264 and 137 proteins using the conventional method with urea at $37^{\circ}C$ for 16h, the PCT-assisted digestion with urea at $25^{\circ}C$ for 1 h, and the non-PCT-assisted digestion with urea at $25^{\circ}C$ for 1 h, respectively. A comparison of these results suggests that PCT enhanced the enzyme digestion by permitting better access to cleavage sites on the proteins.

• Asian-Australasian Journal of Animal Sciences
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• v.2 no.3
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• pp.349-350
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• 1989

• Asian-Australasian Journal of Animal Sciences
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• v.2 no.3
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• pp.327-328
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• 1989

• Asian-Australasian Journal of Animal Sciences
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• v.21 no.10
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• pp.1522-1528
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• 2008

The objective of this study was to develop a model for simulating gastric digestion in the pig. The model was constructed to include the chemical and physical changes associated with gastric digestion such as enzyme release, digestion product removal and gastric emptying. Digesta was collected from the stomach cannula of pigs to establish system parameters and to document the ability of the model to simulate gastric digestion. The results showed that the average pH of gastric digesta increased significantly from 2.47 to 4.97 after feed consumption and then decreased 140 min postprandial. The model described the decrease in pH within the pigs' stomach as $pH_t=5.182e^{-0.0014t}$, where t represents the postprandial time in minutes. The cumulative distribution function of liquid digesta was $V_t=64.509e^{0.0109t}$. The average pepsin activity in the liquid digesta was 317Anson units/mL. There was significant gastric emptying 220 min after feed consumption. The cybernetic dynamic system of gastric digestion was set according to the above data in order to compare with in vivo changes. The time course of crude protein digestion predicted by the model was highly correlated with observed in vivo digestion (r = 0.97; p = 0.0001), Model prediction for protein digestion was higher than that observed for a traditional static in vitro method (r = 0.89; p = 0.0001).