Protein hydrolysates from animal processing by-products as a source of bioactive molecules with interest in animal feeding: A review

Industrial processing of livestock, poultry and fish produces a large amount of waste in a solid or liquid form that can either be destroyed or be used to make compost, biogas or other low-added value products. However, the by-products from animal processing industries have a potential for conversion into useful products of higher value, such as protein hydrolysates, with interesting applications in animal feed. Low amounts of animal protein hydrolysates included in aqua-feeds may enhance growth rate and feed conversion of farmed fish and crustacean. Animal protein hydrolysates may also be incorporated in diets to enhance the nonspecific immunity of fish. As well, these hydrolysates can be used as a good source of amino acids for newly weaned animals. Protein hydrolysates from animal by-products including antimicrobials, antioxidants, opioid-like and/or other interesting bioactive molecules have promising and interesting applications on companion and production animals. By-products from animal processing industries are therefore a promising source of bioactive peptides of considerable interest for animal care, always within the framework of the existing legislation. Possible drawbacks and future trends of the use of animal by-products and/or production of protein hydrolysates from those materials are also discussed.     

Efficient synthesis of benzophenone derivatives in Lewis acid ionic liquids

Benzophenone and its derivatives were prepared via Friedel–Crafts acylation reactions using ionic liquids (ILs) of BmimCl–FeCl₃, BmimCl–AlCl₃ and BmimCl–ZnCl₂ as dual catalyst–solvent. Among them, BmimCl–FeCl₃ showed much higher catalytic activity than that observed for the other two ILs, and in conventional organic solvents. In these reaction systems, good to excellent yields (up to 97%) of acylation products were obtained in a short reaction time. This method features high yield, a simple product isolation procedure, ILs reusability and reduced waste discharge, thus rendering this catalytic system both efficient and environmentally friendly.     

预制菜包装技术的发展概况及趋势

目的 综述预制菜包装材料和技术的应用,为进一步开发预制菜包装提供研究基础。方法 根据国内外预制菜包装的研究进展,介绍预制菜包装主要的材料和技术,及可用于预制菜包装的新型包装技术。结果 目前使用的预制菜包装技术有真空包装和气调包装等,需要加快对预制菜包装技术的研究和新型包装材料的应用,促进预制菜产业的发展和升级。结论 随着预制菜的迅速发展,预制菜的包装受到消费者的更多关注,新型的食品包装技术在预制菜领域具有广阔的发展空间。     

Several melanosis-inhibiting formulas to enhance the quality of deepwater pink shrimp (Parapenaeus longirostris)

The aim of this work was to assess the effect of several melanosis-inhibiting formulations on quality of deepwater pink shrimp (Parapenaeus longirostris) during storage. The formulations tested were as follows: one containing 4-hexylresorcinol (0.1%) in combination with organic acids (citric, ascorbic and acetic) and chelating agents (ethylenediaminetetraacetic acid [EDTA] and di-sodium di-hydrogen pyrophosphate [PPi]); a commercial formula based on sulphites (3%), and another formulation containing a mixture of chitosan (0.3%) and commercial sulphites. Non-treated shrimp were used as control. The 4-hexylresorcinol-based formulation was more effective than 3% of commercial sulphite solutions in preventing melanosis. This treatment prolonged the sensory acceptability of shrimp by up to six days in ice storage. During chilled storage, the treatment with the 4-hexylresorcinol-based formula inhibited the growth of microorganisms by 1.5–2 log cycles as compared to commercial sulphites, especially H₂S-producers and pseudomonads. At the end of the experimental period, TVB-N levels were slightly higher in the lot treated with 4-hexylresorcinol (33 mg/100 mg) and reflected greater endogenous enzymatic activity, since the counts of the spoiler microorganisms remained around log 5 cfu/g or even lower. In general, the incorporation of chitosan to sulphites did not improve or produce a marked effect on shrimps during storage. During the sensory analysis, the panellists rated all the lots very similar, although the 4-hexylresorcinol formulation was the only one with a neutral odour at the end of the period. The 4-hexylresorcinol-based formulation induced yellow-green colorations to some extent in the cephalothorax, possibly due to the effect of organic acids and chelants, while the rest of the lots presented greyish/blackish colorations. Therefore, the formulation based on 4-hexylresorcinol may safely substitute traditional sulphites to improve the quality of fresh shrimp and prolong their shelf life during storage.     

不同pH条件下乳清蛋白-桑椹多酚复合营养粉的制备及其理化性质

近年来,蛋白质与多酚类物质的相互作用是食品领域的研究热点之一,两者的结合受到多种因素的影响,其中pH值是重要的影响因子。该文研究了不同pH值条件下桑椹多酚(Mulberry Polyphenols,MP)对乳清蛋白(Whey Protein,WP)理化性质和功能特性的影响。结果表明,桑椹多酚改变了复合蛋白粉的色泽、粒径大小和Zeta电位。同时,还提高了乳清蛋白的溶解性、乳化性能,在pH值3.0时乳清蛋白的乳化能力和乳化稳定性分别达到7.23 m²/g prot和89.56%,较对照组分别提高了2.66%和1.21%。通过高效液相色谱法对桑椹多酚-乳清蛋白粉中的单体酚类进行定量分析,在pH值5.0和7.0条件下结合的单体酚含量比pH值1.0和3.0高。此外,较空白对照组而言,添加桑椹多酚提高了乳清蛋白的DPPH自由基清除率、ABTS⁺自由基清除能力和FRAP还原能力,最高分别达到89.28%、81.70%和530.95μmol/g prot。综上所述,利用动物蛋白结合植物多酚是创新功能食品组分的手段,反应体系的pH值对结合效率有重要影响,为今后...     

太子参化学成分及生物活性研究进展

太子参为石竹科植物孩儿参的干燥块根,味甘、微苦,性平,归脾肺经,具有益气健脾、生津润肺之功效,常用于气虚津伤的肺虚燥咳,被国家卫生健康委员会批准用于保健食品。现代药理和临床研究表明,太子参中特征性化学成分多糖和环肽具有免疫调节、抗炎、改善记忆等作用。近年来对太子参的化学成分、结构和药理作用的综述仅局限于特征成分,对其他成分还鲜有系统梳理报道。因此本文系统梳理了太子参的化学成分及生物活性研究进展,以期为太子参的开发利用提供参考和依据。     

低温等离子体对水产品常见微生物灭活效果影响的研究进展

水产品极易腐败变质,需要采取一定的措施抑制其腐败变质。低温等离子体（Cold Plasma,CP）作为一种新型高效的广谱冷杀菌技术,可以在大气压下实现均匀、稳定放电,且对常见水产品致病菌和腐败菌具有较好的杀灭效果,可以延长水产品的货架期。作者综述了CP产生方式、灭活微生物机制及影响其灭菌效果的因素,同时探讨了CP对不同种微生物的杀灭效果及对水产品品质的影响,以期为CP在水产品保鲜中的应用提供参考。     

微生物工程教学改革的探索和实践

结合＂微生物工程＂课程的教学实践,优化教学内容、改进教学方法以及加强实践教育等方面的改革措施,以期达到提高了教学质量、提升学生的综合素质和创新能力的目的。     

发酵工程实验“研究型+趣味”教学方式探索

微生物发酵工程实验是生物技术、生物工程专业的主干实验课程,为激发学生学习兴趣、提升教学质量,本文作者在生物技术专业(生物制药方向)本科生的该课程教学中,以抗生素发酵上下游工程为主线,在教学大纲设计、课堂教学与多种形式课外科技实践的结合以及课程考核内容与评价方式等方面尝试了研究型、趣味性教学方式的运用,取得了较好的效果。     

蜡状芽孢杆菌产中性蛋白酶发酵条件的优化

为提高蜡状芽孢杆菌(Bacillus cereus)发酵产蛋白酶的能力,对发酵培养基组成及培养条件进行优化。通过单因素试验研究最适C源及其添加量、最适N源及其添加量、温度、种龄、摇床转速、装液量、pH、时间、接种量等条件对菌株产蛋白酶的影响。在此基础上,利用正交试验设计从9个影响因素中筛选3个主要影响因素,即蛋白胨添加量、温度和装液量;再利用Box-Behnken试验设计进行响应面分析,最终确定蜡状芽孢杆菌发酵产酶条件的最优条件为:蛋白胨添加量7.9g/L,温度26.7℃,装液量56.4mL。优化后,蛋白酶活力达到753.67U/mL,比初始蛋白酶活力(249.50U/mL)提高了2.02倍。