青海牧区高寒草甸草地放牧藏羊肉品质分析

研究青海藏羊和小尾寒羊的肉营养品质、氨基酸含量。结果表明:藏羊肉蛋白质含量为21.96%,极显著高于小尾寒羊肉(P<0.01);脂肪含量为2.66%,显著低于小尾寒羊肉(P<0.05);氨基酸总量、非必需氨基酸含量分别极显著高于小尾寒羊肉(P<0.01),必需氨基酸含量显著高于小尾寒羊肉(P<0.05),特别是藏羊肉中谷氨酸含量显著高于小尾寒羊肉(P<0.05);说明藏羊属于高蛋白质、低脂肪、氨基酸含量丰富的动物性食品,符合当今人们对优质健康肉食品的要求。

The Content Variations of Main Nutrients in Storage Root Expanding Stages of Sweet Potato and Their Mutual Relationships

[Objective] The content variations of the main nutrients in storage root during expanding stages and their mutual relationships in orange-fleshed sweet pota-to （Ipomoea Batatas（L.） Lam） were studied in this paper. [Method] The dynamics of main nutritional ingredients in orange-fleshed sweet potato-variety at 40, 70, 100 and 125 days after transplanting were investigated, and these traits included the 6- carotene content, Fe content, Zn content, starch content, protein content, glucose content, fructose content, and sucrose content. The relationships among these nutri- ents were analyzed during whole developing stage. [Result] B-carotene content in the whole growth period showed straightly increasing firstly, and then decreasing trend, which was unimodal fluctuation curve. The variation tendency of protein con- tent was gently decreasing firstly and then ascending. The dynamics of starch con- tent was similar to l^carotene content, while the fluctuation was stable. The chang- ing curve of carbohydrate was opposite to starch, showing decreasing firstly and then ascending. Fe content was decreasing all the whole developing stage, falling fast and then slowing down. Moreover, Zn content was plummeting. The sucrose content in fresh storage root had significantly negative correlation with β-carotene content, and had positive correlation with fructose content. Starch content had significantly negative correlation with fructose content, and had positive correlation with Zn content. [Conclusion] These research conclusions could guide the variety to har- vest at suitable time, so as to achieve the aim of micronutrition improvement.

Slaughter Performance, Muscle Quality and Muscle Nutrients of Twelve-month-old Tibetan Goat

This study aimed to study the germplasm characteristics of Tibetan goat distributed in Sichuan. Three male and three female goats of twelve-month-old Ti-betan goat were selected, and they were slaughtered for analysis of slaughter per-formance, muscle quality and muscle nutrients. The results showed that the pre-slaughter body weights, dressing percentages, meat percentages and carcass meat production rates of male and female Tibetan goats were （14.33±1.53） and （12.50±2.18） kg, （42.11±5.26）% and （43.85±4.51）%, （31.34±3.36）% and （32.84±3.16）%, and （72.34±0.54）% and （72.30±0.78）%, respectively. There were smal differences in car-cass size, carcass segmentation, muscle fiber properties, muscle quality, muscle nu-tritional composition, muscle minerals contents and muscle heavy metals contents between male and female Tibetan goats. A total of 18 kinds of amino acids were detected in the muscle of male and female Tibetan goats. The EAA/TAA ratios and EAA/NEAA ratios of male and female Tibetan goats were （39.18＆#177;0.38）%and （38.70±0.72）%, and （64.31±1.03）% and （63.21±1.92）%, respectively.

A Review of Factors Influencing Intramuscular Fat Content in Porcine Meat

Intramuscular fat （IMF）, an important flavor precursor of porcine meat, is closely related to pork quality traits such as pH, color, tenderness, water-holding capacity （WHC） and juiciness, and thus is one of the important factors affecting pork quality. Pork IMF content is not only associated with swine breed on heredity, but also influenced by the alteration of nutrients in diet. These may give a possibility for researchers to improve the IMF content and pork quality by their work on swine breed or heredity, and nutrition regulation in diet. Therefore, this article summarizes the effects of swine breed and nutrition regulation on IMF content briefly to provide some information for future researches.

Use of Natural Antioxidants in Meat and Meat Products

Antioxidants are used to minimize lipid oxidation. Antioxidants can act as metal chelators and free radical or oxygen scavengers, which can slow the progression of lipid oxidation. Lipid oxidation may have negative effects on the quality of meat and meat products, causing changes in sensory attributes such as color, texture, odor and flavor, and nutritional quality. Several synthetic antioxidants have been used to successfully prevent lipid oxidation in the meat industry, but consumers are concerned about the health risks related to consumption of some synthetic antioxidants. Therefore, there has been a growing interest in natural antioxidants. Nowadays, compounds obtained from natural sources such as grains, oilseeds, spices, fruit and vegetables have been investigated to decrease the lipid oxidation. In this review, the potential effects of natural antioxidants were evaluated that are widely used in meat and meat products.