HACCP原理在方便面酱包生产中的应用

运用危害分析及关键控制点（HACCP）原理对方便面调味酱包生产过程进行了危害分析及关键控制.结果表明,方便面酱包生产中存在微生物污染、化学污染、物理污染等危害;确定了除豆酱类外的各种原料、投料烹调、包装和卫生状况4个关键控制点,并提出了相应控制措施.     

Fish muscle: the exceptional case of notothenioids

Fish skeletal muscle is an excellent model for studying muscle structure and function, since it has a very well-structured arrangement with different fiber types segregated in the axial and pectoral fin muscles. The morphological and physiological characteristics of the different muscle fiber types have been studied in several teleost species. In fish muscle, fiber number and size varies with the species considered, limiting fish maximum final length due to constraints in metabolites and oxygen diffusion. In this work, we analyze some special characteristics of the skeletal muscle of the suborder Notothenioidei. They experienced an impressive radiation inside Antarctic waters, a stable and cold environment that could account for some of their special characteristics. The number of muscle fibers is very low, 12,700–164,000, in comparison to 550,000–1,200,000 in Salmo salar of similar sizes. The size of the fibers is very large, reaching 600 μm in diameter, while for example Salmo salar of similar sizes have fibers of 220 μm maximum diameter. Evolutionary adjustment in cell cycle length for working at low temperature has been shown in Harpagifer antarcticus (111 h at 0°C), when compared to the closely related sub-Antarctic species Harpagifer bispinis (150 h at 5°C). Maximum muscle fiber number decreases towards the more derived notothenioids, a trend that is more related to phylogeny than to geographical distribution (and hence water temperature), with values as low as 3,600 in Harpagifer bispinis. Mitochondria volume density in slow muscles of notothenioids is very high (reaching 0.56) and since maximal rates of substrate oxidation by mitochondria is not enhanced, at least in demersal notothenioids, volume density is the only means of overcoming thermal constraints on oxidative capacity. In brief, some characteristics of the muscles of notothenioids have an apparent phylogenetic component while others seem to be adaptations to low temperature.     

越冬池冰下水体沉积物理化性质的初步研究

我国北方地区鱼类越冬池在整个越冬期间冰下水体沉积物积累厚度为０．８～２．０ｃｍ，相当于每平方米水面积累沉积物湿重９．６千克，干重２．８千克，其含水率为７１．５％；沉积物的ｐＨ值在６．３～７．２之间。沉积物中有机物含量和氮、磷、钾等营养元素含量比农业土壤中的含量高得多，有机物含量与总氮含量之间存在明显的正相关关系（γ＝０．９８９，ｎ＝１２）。越冬期的沉积物耗氧速率比其他季节低得多，但仍须重视；其耗氧速率与有机物含量之间存在中等强度的相关关系（γ＝０．６４８，ｎ＝１２）。     

Diet-induced milk fat depression: Association with changes in milk fatty acid composition and fluidity of milk fat

This experiment was designed to examine changes in milk fatty acids during fish oil-induced milk fat depression (MFD) and to test the theory that these changes are related to milk fat fluidity. The experiment was divided into three periods: 1) Baseline: all cows (n = 12) received a high fiber diet without fish oil (FO) for 12 days; 2) Treatment: 4 cows/group received the following treatments for 21 days: a) Low fiber diet without FO (LF), b) High fiber diet + FO (HF + FO) and c) Low fiber diet + FO (LF + FO); 3) Post-treatment: cows returned to the baseline diet and were monitored for 12 days. FO was included at 1.6% DM and HF and LF diets had 40 and 26% NDF, respectively. Milk fat content and yield were unchanged by the LF diet, but were reduced by FO diets at both dietary fiber levels and recovered in the post-treatment period. FO diets caused a pronounced reduction in stearic and oleic acid concentrations in milk fat and an equally pronounced increase in trans-18:1 fatty acid concentrations. Milk fat mean melting point (MMP) was correlated with MFD (r = 0.73) and with milk oleic acid concentration (r = − 0.92). The ratio of oleic:stearic in milk fat increased gradually and consistently in response to FO. Trans-C18:1 isomers with double bounds at carbon ≤ 10 increased with greater MFD and those with double bonds at carbon ≥ 11 decreased with greater MFD. Trans-9 cis-11 CLA explained more than 80% of MFD and was strongly correlated with trans-10 C18:1. Maintenance of MMP below 39–40 °C suggests that the mammary gland was able to secrete only milk fat with adequate fluidity and that MFD could be an adaptation mechanism to prevent secretion of milk with higher MMP.     

Characterization and Cryoprotection of Invasive Silver Carp (Hypophthalmicthys molitrix) Protein Hydrolysates

ABSTRACT

Silver carp (Hypophthalmicthys molitrix) is regarded as an invasive, underutilized freshwater fish causing environmental and economic complications along the U.S. Mississippi River System. In this study, silver carp protein hydrolysates (FPH) were obtained from 30, 60, 90, 120, and 240 min hydrolysis with Protamex®. Amino acid composition showed polar amino acids, including Asp and Glu, and freed hydrophobic residues in FPH-90 and FPH-240. Protein surface hydrophobicity of FPH increased with increasing degree of hydrolysis. Cryoprotection was evaluated using a muscle (mince) food system with 6% FPH (w/w) from each hydrolysis time condition, an untreated mince (CTRL), and 8% (w/w) 1:1 sucrose-sorbitol (SUSO), respectively. After six freeze-thaw cycles (D7), all FPH treatments had lower (p < 0.05) expressible moisture, indicating strong water-holding capacity by the FPH. FPH formulations also imparted antifreeze activity equal to or better than SUSO, with the FPH-90 exhibiting higher (p < 0.05) proportion (43.9%) of unfrozen water at D7. Results from this study provide preliminary evidence for development of effective cryoprotectants using an underutilized, invasive fish species that can be exploited for environmental and economic gain in the form of value-added ingredients and further provide opportunities to understand the fundamental physicochemical properties governing cryoprotection of FPH in a frozen mince system.     

工厂化循环水养鱼工程技术研究与开发

对封闭式循环水养鱼水处理系统的工艺流程及设施设备现状作了论述,指出生物净化技术及设备在机理研究与参数量化上尚需深入探讨,提出了今后研究发展的方向。重点对目前国内应用的5种模式陆基养殖系统工程的特点、技术路线、适用范围做了研究分析,以供养殖企业在新建或改造养殖设施时选择参照。     

Dietary Soy Saponin Improves Antioxidant and Immune Function of Layer Hens

The objective of this study was to determine the effects of dietary soy saponin (SS) on the antioxidant and immune functions of laying hens. Two hundred seventy 22-week-old Hy-line gray layers were randomly allocated into three treatment groups: a control group (Control) fed a basal diet with low soybean meal and groups supplemented with 50 and 500 mg/kg SS (50 SS and 500 SS). After ten weeks, eight chickens from each treatment group were anesthetized and sacrificed to collect tissue samples. In the 50 and 500 SS groups, results showed that the levels of superoxide dismutase (SOD) in serum and spleen were elevated, and the content of malondialdehyde (MDA) in serum decreased. The mRNA levels of genes such as NF-E2-related factor 2 (Nrf-2) in the ileum and Nrf-2 and SOD in the spleen were also upregulated. In addition, the skin irritation index of phytohemagglutinin (PHA), the number of serum white blood cells, and lymphocytes were elevated in the two groups. At the same time, the number of monocytes in the blood increased in the 50 SS group, and it was significantly higher in the 500 SS group. In addition, the mRNA levels of lysozyme (LYZ) and IFN-γ in the spleen were upregulated, similar to the mRNA levels of zinc finger protein A20 (A20) in the ileum. Furthermore, the mRNA levels of NF-κB and IL-6 in the ileum were downregulated. In conclusion, with supplementation of 50 and 500 mg/kg SS in low soybean meal diets, the antioxidant, and immune functions of laying hens were improved. More importantly, the target for SS to exert biological effects on laying hens may be in the intestine and spleen tissues.