• Food Science of Animal Resources
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• v.38 no.4
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• pp.693-702
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• 2018

The purpose of this study was to develop a commercially viable method for synthesis of conjugated linoleic acid (CLA) using the linoleic acid fraction obtained from six pork by-products (liver, lung, heart, stomach, small intestine, and large intestine). The workflow of CLA synthesis from each by-product was as follows: washing${\rightarrow}$crude fat extraction${\rightarrow}$fractionation into saturated and unsaturated fatty acids${\rightarrow}$repeat unsaturated fatty acid fractionation${\rightarrow}$CLA synthesis. Cis-9, trans-11, and trans-10, cis-12 CLA was synthesized from pork by-products. The yield of CLA synthesis of pork by-products ranged from 1.55 to 11.18 g per 100 g of by-products. The amount of synthesized CLA was the highest in the small intestine and large intestine by-products. Fractionation of pork by-products nearly doubled the yield of CLA. We suggest that commercial fractionation methods could increase the yield of CLA at low cost, reduce waste, and improve the efficiency of by-product utilization.

• The Korean Journal of Food And Nutrition
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• v.2 no.1
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• pp.12-17
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• 1989

This experiment was carried out to investigate the changes in quality of pork organs such as the meat of large intestine, small intestine and liver during frozen storage at -18$\pm$1$^{\circ}C$. The result obtained were as follows ; 1 The moisture contents in the meat of large intestine, small intestine and liver was 61.1%, 65.1% and 71.3% and the content of crude fat was 27.1%, 21.5% and 5.0% respectively, 2. Weight loss increased In the course of storage period, and liver showed the least weight loss in them. 3. Total lipid in the meat of large intestine, small intestine and liver was 24.4%, 19.2% and 4.3% respectively, and which decreased gradually in the course of storage period. 4. The content of volatile basic nitrogen in raw meat was 20 mg% within and without before storage treatment, and that of the value was 24.2 mg% within after 3 weeks storage.

• Food Science of Animal Resources
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• v.34 no.3
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• pp.297-306
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• 2014

Basic information regarding the yield and nutritional composition of edible pork by-products, namely heart, liver, lung, stomach, spleen, uterus, pancreas, and small and large intestines, was studied. Our results revealed that the yields varied widely among the pork by-products examined; in particular, liver had the highest yield (1.35%); whereas, spleen had the lowest yield (0.16%). The approximate composition range (minimum to maximum) of these by-products was found to be: moisture 71.59-82.48%; fat 0.28-19.54%; ash 0.155-1.34%, and protein 8.45-22.05%. The highest protein, vitamin A, B2, B6, and total essential amino acid (EAA) contents were found in liver. Large intestine had the highest fat content and lowest EAA content. Heart had the highest vitamin B1 content, whereas pancreas had the highest niacin and vitamin B3 contents. The concentrations of Fe and Zn were highest in liver and pancreas. Total saturated fatty acids (SFA) levels and polyunsaturated fatty acids (PUFA) levels between the by-products ranged from 43.15-50.48%, and 14.92-30.16%, respectively. Furthermore, with the exception of large intestine, all the by-products showed favorable PUFA/SFA ratios. The study indicated that almost all of the pork by-products examined were good sources of important nutrients, and that these data will be of great importance in the promotion of the consumption of edible pork by-products, as well as their utilization in meat processing.

• Food Science of Animal Resources
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• v.42 no.2
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• pp.332-340
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• 2022

The objective of this study was to determine the optimal cooking time by considering the cooking loss, shear force, and off-odor reduction of pork large intestines. Commercial pork large intestines were purchased, quartered perpendicularly, and cooked in boiling water for 40, 120, 180, and 240 min. Cooking loss of the samples increased after 240 min of cooking (10.92, p<0.05) while shear force value was lower at 240 min (4.45) compared to that at other cooking times (p<0.001). The amount of major volatile organic compounds showed a decreasing trend with increasing cooking time. In particular, the amount of methyl pentanoate (17,528.71) and methyl isobutyrate (812.51), compounds with a relatively low odor threshold, decreased significantly after 120 min of cooking and no change was observed thereafter (p<0.05). In addition, the amount of 2-pentanol (3,785.65) and 1-propanol (622.26), possibly produced by lipid oxidation, significantly decreased at the same cooking time (p<0.001). In the principal component analysis, only the 40 min cooking time was significantly different from other cooking time by high amounts of 1-propanol, 2-pentanol, and methyl isobutyrate. In conclusion, in the present study, the optimal cooking time for pork large intestines was 120 min in terms of off-odor reduction, cooking loss, and shear force.

• Journal of Veterinary Science
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• v.22 no.3
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• pp.31.1-31.12
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• 2021

Background: Blackened intestines in slaughtered pigs have been commonly observed in China in recent years. However, no cause has been reported. Objectives: We attempted to determine whether the blackening of the pig intestine was related to an excess of copper (Cu) in their feed. Methods: In this study, we observed and collected porcine intestines in small- and large-scale pig slaughterhouses in Shandong province from May to October 2018. Twelve types of metal ions were detected in the black intestinal samples. Results: The Cu level in the intestine samples was mostly higher than the Chinese national limit for food. Further study showed that Cu supplementation in most commercial porcine feed also exceeded the national standard. An animal model (mouse) that could mimic the intestinal blackening in pigs was established. Compared to control mice, Cu accumulated in the liver and intestines of mice fed an excessive Cu level, confirming the excessive Cu in the feed may be considered the major cause of blackened porcine intestines. Microscopic examination revealed that black intestines had many particles containing Cu in the lamina propria of the intestinal mucosa, and the intestinal mucosal epithelial cells showed degeneration and necrosis. Conclusions: In conclusion, overuse of Cu in animal feed can lead to animal poisoning and Cu accumulation in animal products. Such overuse not only harms the health of livestock but can also affect public health.