长角豆胶复合涂膜保鲜剂常温保鲜荔枝的研究

本实验以长角豆胶与黄原胶复配胶为涂膜基质,CMC-Na、柠檬酸和吐温80等为成膜助剂,配以丁香、艾叶和大黄等具有抗菌作用的中草药制剂,配制成中草药复合涂膜保鲜剂,研究了常温(均温30.50℃)下该复合涂膜保鲜剂对荔枝品质变化的影响.结果表明:常温下经该保鲜剂涂膜保鲜的荔枝与对照组相比,果实腐烂率、失重率明显降低,呼吸强度、PPO活性及营养成分的消耗被抑制,延缓了果实的衰老过程.     

槐豆胶和猪屎豆胶与黄原胶复合涂膜保鲜剂对杨梅贮藏品质的影响

以槐豆胶和猪屎豆胶与黄原胶为涂膜基质,以山梨酸、甘油为成膜助剂,配制成复合涂膜保鲜剂,研究了常温(28～32℃,相对湿度68%～86%)下该复合涂膜保鲜剂对杨梅贮藏品质变化的影响。结果表明:常温下经槐豆胶和猪屎豆胶与黄原胶复合涂膜保鲜剂涂膜贮藏的杨梅与对照组相比,果实裂果率、霉烂率、失重率明显降低,抑制了果实的呼吸率;有机酸、VC等营养成分转化、流失的速度减慢,有效地降低MDA、花青素含量和相对电导率的升高,使PPO、POD、PAL酶活性处于较低的水平,延缓了果实的衰老,从而延长了其货架期。综合考虑,槐豆胶与黄原胶涂膜保鲜剂的效果优于猪屎豆胶与黄原胶复合涂膜保鲜剂。     

银合欢种子胶涂膜保鲜杨梅研究

以银合欢种子胶为涂膜基质,甘油作为成膜助剂,配制成复合涂膜保鲜剂,研究常温(28～32℃),相对湿度68%～86%条件下该复合涂膜保鲜剂对杨梅品质及其生理生化变化的影响。结果表明：常温下经复合涂膜保鲜剂涂膜保鲜的杨梅与对照组相比,果实裂果率、失重率降低,果实好果率和硬度明显增加, 抑制了果实的呼吸率;有机酸、VC 等营养成分变化速度减慢,有效地降低MDA、花青素含量,使PAL 酶活性处于较低的水平,延缓了果实的衰老过程。     

刺槐豆胶复合涂膜保鲜剂低温保鲜荔枝的研究

以长角豆胶与黄原胶复配为涂膜基质,CMC-Na、柠檬酸和吐温-80等为成膜助剂,配以丁香、艾叶和大黄等抗茵作用成分.配制成复合涂膜保鲜剂,研究低温(均温为-4℃)下该复合涂膜保鲜剂时荔枝品质变化的影响.结果表明:低温下经长角豆胶复合涂膜保鲜剂保鲜的荔枝与对照组相比,果实腐烂率、失重率明显降低,呼吸强度、PPO活性及营养成分的消耗被抑制,延缓了果实的衰老过程.     

丁香、艾叶提取物与长角豆胶复合涂膜保鲜剂对杨梅耐藏性的影响

以长角豆胶、黄原胶复配胶为涂膜基质,配以丁香、艾叶等具有抗菌作用的中草药制剂,配制成中草药复合涂膜保鲜剂,以杨梅为保鲜目标,常温下对其进行保鲜实验,研究该保鲜剂对杨梅品质变化的影响。结果表明：经该保鲜剂涂膜处理的杨梅与对照组相比,果实的腐烂率、呼吸强度明显被抑制,有机酸、可溶性固形物等营养成分能较好地保存,贮藏到第5 天时,好果率为80%。     

蜈蚣藻多糖与卡拉胶复合涂膜保鲜剂影响杨梅常温贮藏的影响

以蜈蚣藻多糖和蜈蚣藻多糖与卡拉胶复配胶为涂膜基质,以CaCl2 和甘油为成膜助剂,配制成复合涂膜保鲜剂,研究常温(28～32℃)、相对湿度68%～86% 条件下该复合涂膜保鲜剂对杨梅品质及其生理生化变化的影响。结果表明：常温下经蜈蚣藻多糖和蜈蚣藻多糖与卡拉胶复合涂膜保鲜剂涂膜保鲜的杨梅与对照组相比,果实裂果率、霉烂率、失重率明显降低,抑制了果实的呼吸率;有机酸、VC 等营养成分转化、流失的速度减慢,有效抑制了MDA、花青素含量和相对电导率的升高,使PPO、POD、PAL 酶活性处于较低的水平,延缓果实的衰老过程。其中,蜈蚣藻多糖涂膜保鲜剂的效果优于蜈蚣藻多糖与卡拉胶复合涂膜保鲜剂。     

中草药复合涂膜保鲜剂保鲜枇杷的研究

本实验以刺槐豆胶与黄原胶复配胶为涂膜基质,分别加入中草药制剂丁香、大黄和艾叶及成膜助剂,配制成两种中草药复合涂膜保鲜剂,并以枇杷为实验材料,研究中草药复合涂膜保鲜剂对枇杷品质变化的影响。结果表明:经过涂膜的枇杷,腐烂程度较低,呼吸速率明显被抑制,VC、有机酸、可溶性固形糖等营养成分能较好地保存。其中配方B保鲜效果最显著。     

南姜精油复合涂膜对番荔枝果实储藏品质的影响

采用南姜精油复合涂膜材料对番荔枝果实进行包装,检验南姜精油复合涂膜的机械性能及其对常见腐败致病菌黑曲霉的抑菌性能,选取霉变率、失重率、还原糖含量、淀粉含量、可溶性果胶和不可溶性果胶含量、呼吸强度、乙烯释放量、淀粉酶活性、多聚半乳糖醛酸酶(PG)、纤维素酶(Cx)活性等生理生化指标对果实涂膜保鲜效果进行综合评价。通过试验结果表明使用南姜精油复合涂膜能够有效降低番荔枝果实的失重率、霉变率、裂果率,抑制细胞壁代谢相关酶类活力,延缓果皮多糖类物质降解,尽量保持果皮完整性和硬度,适度延长果实保鲜期,尽可能地保证果实原有的口感和品质,12.5%南姜精油是复合涂膜的最佳添加量,保鲜效果最佳。     

苦豆子半乳甘露聚糖复合涂膜保鲜剂对黄樱桃常温贮藏效果的影响

本实验以苦豆子半乳甘露聚糖为成膜基质,添加适量的CaCl2和柠檬酸为增塑剂,以甘油为成膜助剂,制备可食性复合膜。研究了常温(温度25-28℃,相对湿度68-75%)下该复合涂膜保鲜剂对樱桃品质及其生理生化变化的影响。结果表明:常温下苦豆子半乳甘露聚糖复合涂膜保鲜剂涂膜保鲜的樱桃与对照组相比,果实裂果率、霉烂率、失重率明显降低,抑制了果实的呼吸率,有机酸、Vc等营养成分转化、流失的速度减慢,有效的降低MDA、花青素含量和相对电导率的升高,使PPO和POD酶活性处于较低的水平,延缓了果实的衰老,从而延长了其货架期。     

壳聚糖涂膜保鲜菠菜研究

采用以壳聚糖为主要原料的涂膜保鲜剂对菠菜进行涂膜保鲜.在冷库条件下,分别以未涂膜空白对照组和不同浓度下的壳聚糖复合保鲜剂对菠菜进行涂膜保鲜处理,测定贮藏期间菠菜的感观指标、失重率、丙二醛(MDA)、固形物、总糖、粗纤维和Vc等理化指标.结果表明,壳聚糖复合保鲜剂能有效减少菠菜中营养成分的损失,降低失重率、抑制MDA的积累,延缓菠菜的腐败.     

可食性活性涂膜在鲜切果蔬保鲜中的应用

可食性涂膜是一种由天然可食性材料制成的选择透过性薄膜,具有调节果蔬内部气体交换、减少水分损失、降低腐烂率及延长货架期的特性,在果蔬包装及保鲜领域中已引起广泛关注。鲜切果蔬具有新鲜、方便、快捷等特点,已在全球范围内广泛供应餐饮业及零售业。可食性涂膜作为多种食品添加剂的载体常应用于生鲜产品中,且将活性添加剂与可食性涂膜结合可以延长鲜切果蔬的货架期,提高果蔬品质,减少果蔬表面致腐及致病菌增长的风险。可食性活性涂膜将作为一种绿色、安全、营养的保鲜技术,并将应用于鲜切果蔬保鲜领域的研究。本文综述了可食性涂膜的分类及其添加的抗菌剂、抗氧化剂、塑形剂、营养素等活性成分在鲜切果蔬保鲜中的应用,旨在开发用于鲜切果蔬保鲜的功能性可食性涂膜。     

黄连壳聚糖复合涂膜保鲜剂对夏橙保鲜效果的研究

为明确可食性涂膜保鲜剂取代常规处理保鲜柑橘的可能性,研究黄连淀粉壳聚糖复合涂膜剂对奥林达夏橙(Citrus sinensis (L.) cv. Olinda Valencia orange)保鲜的效果。结果表明：复合涂膜可以明显降低贮藏期间夏橙病害指数和质量损失率,保持较高的好果率;复合涂膜处理可以降低果实的呼吸强度,维持果实内部较高的可滴定酸和VC含量,可溶性固形物含量变化较小,保持果实较高的营养品质;复合涂膜可以提高果实中过氧化氢酶活性,且在贮藏后期过氧化氢酶活性和超氧化物歧化酶活性明显高于常规方法处理,有效抑制丙二醛的积累,保持细胞膜的完整性。以上研究表明复合涂膜在延缓夏橙贮藏期间果实品质劣变和衰老方面已达到常规处理的保鲜效果,且食用安全、环境友好,具有替代夏橙果实常规保鲜的潜在应用价值。     

普鲁兰多糖复合抑菌涂膜剂的制备及其对鸡蛋的保鲜效果

为延长鸡蛋货架期,以普鲁兰多糖为原料,通过添加甘油、阿拉伯树胶、溶菌酶和几丁质酶,并结合超声工艺制备成可食性复合涂膜保鲜剂。通过水蒸气透过系数和过氧化值的测定,研究各成膜剂质量比、膜液质量浓度、干燥时间、干燥温度和超声时间等因素对普鲁兰多糖复合膜性能的影响。结果表明：普鲁兰多糖、甘油、阿拉伯树胶质量比为3∶1∶2,成膜剂质量浓度为3.0～3.3 g/100 mL、干燥温度60 ℃、干燥时间90 min、150 W超声处理15 min、添加0.75 g/100 mL溶菌酶与几丁质酶（质量比1∶3）,此时普鲁兰多糖复合涂膜剂的性能表现最佳,且能有效抑制大肠杆菌、金黄色葡萄球菌、沙门氏菌毛霉和曲霉的生长。在鸡蛋保鲜实验中,25 ℃存放28 d后涂膜组的鸡蛋质量损失率为6.16%,蛋黄指数为0.31,哈夫值下降至67.18,蛋清pH值由7.61上升至8.47,涂膜组鸡蛋品质仍维持在A级水平。综上,普鲁兰多糖复合抑菌涂膜剂具有良好的保鲜效果,能有效抑制腐败细菌和真菌生长。     

The chemistry of lysozyme and its use as a food preservative and a pharmaceutical

The chemistry and use of lysozyme as a food preservative and a pharmaceutical are reviewed. Lysozyme inhibits the growth of deleterious organisms, thus prolonging shelf life. Chemicals used to improve the preservative effect of lysozyme and those that inhibit the enzyme are discussed, along with the stability of lysozyme in various chemical environments. Lysozyme has been used to preserve fresh fruits and vegetables, tofu bean curd, seafoods, meats and sausages, potato salad, cooked burdock with soy sauce, and varieties of semihard cheeses such as Edam, Gouda, and some Italian cheeses. Lysozyme added to infant-feeding formulas makes them more closely resemble human milk. Lysozyme has been used clinically in the treatment of periodontitis, administered in chewing gum, and implemented to prevent tooth decay. It has also been administered to patients suffering from cancer for its analgesic effect and has been used as a potentiating agent in antibiotic therapy.     

可食性膜降低油炸鱼块含油量的研究

通过研究3 种可食性膜对降低油炸鱼块含油量的影响,探讨不同可食性膜、可食性膜在挂糊时的添加次序、可食性膜的质量分数以及不同比例的混合可食性膜复配后对油炸鱼块含油量的影响及其抑油效果。研究表明：3 种可食性膜与对照组相比均有显著的抑油效果(P ＜ 0.05),其中羧甲基纤维素钠(CMC-Na)效果最好,海藻酸钠次之,阿拉伯胶最小,其质量分数2% 的抑油率分别达到21.33%、16.97% 和9.99%;3 种可食性膜均在挂糊中添加的抑油效果最好;复配后按照CMC-Na:海藻酸钠=1:2 的比例配制的挂糊液抑油效果最好,其1% 质量分数的抑油率达到34.54%。     

Food preservative content reduction by controlling sorbic acid release from a superficial coating

In the aim to reduce the total amount of preservatives added in food, edible coating is used in the present study as surface retention of active agents to maintain a local high effective preservative concentration where microorganisms are intended to contaminate and/or grow, i.e. on coating surface. A food/anti-microbial coating system with sorbic acid as the active compound, agar gel as model food and wheat gluten (WG) or beeswax (BW) film as edible coatings was studied. A mathematical model able to describe the release kinetics of the anti-microbial agents from the edible coating into food products was developed and validated. It was used for estimating the local surface concentration in sorbic acid of coated model food. This surface concentration is an essential value for predicting microorganism growth but cannot be evaluated by experiments. In the case of WG coating, the surface concentration drops below 10% of the initial value after 1 h whereas in the case of the BW coating, the surface concentration remains above 75% even after one week of contact. Simulation realized using the estimated surface concentration and a simplified equation for the growth inhibition kinetics of Saccharomyces cerevisiae were compared to microbiological efficacy assessment. The calculated amount of sorbic acid required to maintain a 0.2% surface concentration during 23 days was 100 times lower when introducing the additive in a beeswax thin layer than directly in the core of the high moisture food or in a hydrophilic film such as wheat gluten.Industrial relevanceThe methodology presented in this study based on experimental measurements and mathematical predictions is of great interest for the rational design of anti-microbial coatings and could be used in industrial applications. Edible coatings are already used in commercial practice for their barrier properties (water barrier property for example to avoid remoistening or drying of cereal-based products, gas barrier properties for the coating of fresh fruits and vegetable, etc) or for food appearance improvement (brilliance of apples for examples could be improved using polysaccharide-based film). Edible coatings have proved to be suitable as vector of preservatives such as anti-microbial or anti-oxidants. By using such retention matrices, very small amount of additives is required since the preservative is concentrated at the product surface. The benefit of using anti-microbial edible coating for consumer health is consequently non-negligible and this aspect is more and more taken into account by food manufacturers. The use of active edible coatings at an industrial scale is expected to grow, in Europe, due to the European framework regulation (EC 2004/1935) which authorizes the concept of active packaging with intentional active agents' release.The efficacy of anti-microbial edible coating could be assessed through time-consuming experimental tests. But most of the time, the couple edible matrix/active compound suitable for one applicable won't be anymore suitable for another food product and empirical tests should be undertaken once more by the food manufacturer. By using an integrated approach such as the one presented in this work, based on mathematical model for predicting additive release kinetics, numerous experiments may be avoided, since once the preservative diffusivity values in the coating and the food are known, the numerical tool could be used to optimize the initial quantity of preservative to add in the coating, to predict the food shelf life as a function of coating thickness or coating concentration in preservative, etc. The data shown in this paper concerning wheat gluten- and beeswax-based films could be also added in data bases of industrial relevance for further commercial applications.The approach used in this study could be considered as an assistant and prediction tool that should (i) optimize food preservation and (ii) help manufacturers in elaboration of new food product and packaging.     

羊肉涂膜保鲜工艺优化

以新鲜羊肉为原料,以玉米醇溶蛋白为成膜剂,以玉米须黄酮、沙棘叶多酚为复合涂膜保鲜剂,以色差值△Eab、菌落总数、pH值和挥发性盐基氮TVB-N值等为考察指标,通过单因素实验及正交实验,确定复合涂膜保鲜工艺。结果表明:成膜剂配比为1 g玉米醇溶蛋白:9 mL体积分数80%乙醇,添加0.1%的玉米须黄酮,0.2%沙棘叶多酚,成膜时间为5 min,在此条件下,鲜羊肉可在4℃保鲜25 d。