高温肉制品杂环胺防控及体内代谢调控研究进展

高温肉制品因具有独特的色泽、香气及口感而备受消费者青睐。但高温肉制品在高温条件下进行加工,其中的还原糖和氨基酸等会通过自由基途径或美拉德反应生成杂环胺等有害物质。本文综述了高温肉制品中杂环胺形成途径、防控方法及其在体内代谢调控的研究进展,基于此提出在热加工过程中应合理选择加工方式、食用油脂、糖及金属阳离子、天然香辛料及抗氧化剂等;摄入体内后应通过降低杂环胺活性、抑制杂环胺活化过程、酶降低杂环胺遗传毒性、核苷酸切除修复降低杂环胺在体内代谢消化吸收率等方法减控杂环胺在体内的消化吸收,调节杂环胺在体内代谢。本文可为优化高温肉制品加工工艺,促进肉制品行业绿色发展和提高消费者健康水平提供依据。     

双酶协同转化龙眼汁中蔗糖生成低聚果糖

目的 探究葡萄糖氧化酶协同果糖基转移酶转化龙眼汁中蔗糖生成低聚果糖、并减少龙眼汁葡萄糖含量的效果,实现减少龙眼汁中热量糖含量制备出低热量龙眼汁。方法 以天然龙眼汁为原料,通过控制不同的酶添加次序、酶添加量、龙眼汁体系pH和酶处理时间的单因素变量法,探究葡萄糖氧化酶协同果糖基转移酶转化龙眼汁中蔗糖生成低聚果糖的较优工艺条件;采用高效液相色谱法测定龙眼汁中游离糖组成及含量。结果 采用两种酶分段处理的方法,控制葡萄糖氧化酶添加量为60 U/g、反应温度为35℃、初始pH值6.0、饱和碳酸钙溶液添加量9.6%、通氧处理时间4 h,可有效消耗龙眼汁中原始葡萄糖和转化过程中产生的葡萄糖,使葡萄糖消耗率达到93.56%,并使龙眼汁中低聚果糖占比由果糖基转移酶单独处理时的31.72%提高到了58.08%。结论 采用葡萄糖氧化酶协同果糖基转移酶处理龙眼汁的方法,能有效降低龙眼汁中热量糖含量,制备出低热量龙眼汁。     

不同处理对猪毛角蛋白提取效果及功能特性的影响

目的 探究不同处理方式对猪毛角蛋白提取效果及功能特性的影响。方法 采取碱解法、酶解法、蒸汽爆破法、还原法4种处理提取猪毛角蛋白,研究不同处理对猪毛溶解率和可溶性蛋白含量以及角蛋白功能特性的影响。结果 碱解和蒸汽爆破处理下猪毛溶解率较高,均为65%左右,而还原法处理的可溶性蛋白含量较高,为165mg/g左右;不同处理对猪毛角蛋白的功能特性影响差异较大,溶解性和持水性较好的分别是碱解和蒸汽爆破处理得到的角蛋白,而还原法提取出的猪毛角蛋白持油性、冻融稳定性、乳化性及乳化稳定性较好。结论 各处理方法均有利弊,需要根据角蛋白的用途选择合适的提取方法。本研究为猪毛角蛋白的提取及猪毛的充分利用提供了一定理论参考。     

Disinfestation of red flour beetle (Tribolium castaneum) present in almonds (Prunus dulcis) using microwave heating and evaluation of quality and shelf life of almonds

Almonds (Prunus dulcis) are one of the high-value nuts facing insect pest infestation predicaments during post-harvest operations and subsequent storage. The red flour beetle (Tribolium castaneum) (Coleoptera: Tenebrionidae) is an economically important and notorious insect pest that globally infest almonds thereby resulting in high storage losses. Currently, the fumigants (hydrogen phosphide and propylene oxide) commonly used during almond storage pose a health hazard to the applicator and consumer as well as the environment. Other disadvantages of chemical methods include chemical residue, high exposure time (2–4 days), pest resistance, the demise of beneficial insects and incomplete disinfestation of the egg stage of the target pest. Among other physical disinfestation methods, the use of microwave as a disinfestation technique offer advantages of less processing time, lower energy consumption, clean technology, and no residues. Therefore to test the efficacy of microwave in pest control of stored almonds, we exposed life stages of T. castaneum to microwave irradiation at different power levels (120–600 W) and durations (30–90 s). Hundred percent mortality of all selected life stages was achieved at 480 and 600 W when infested almonds exposed for 90 and 60 s respectively. The quality attributes of treated almonds such as color difference, water activity, hardness, peroxide value, free fatty acid, and iodine value were measured and found to be acceptable. The fatty acid composition and sensory analysis demonstrated no significant difference (p > 0.05) in control and microwave treated almonds. The storage studies revealed that microwave treated almonds were free from infestation and rancidity for up to 12 months, whereas untreated almonds were spoiled within 3 months.