茶多酚保鲜液对圣女果保鲜效果的研究

该文以圣女果为研究对象,用天然抗氧化物茶多酚作为保鲜剂进行涂膜处理,研究最佳的保鲜浓度。茶多酚浓度分为4组,分别为20、30、40、50 mg/L。共贮存5天,每天测定一次生理生化指标,包括抗坏血酸、丙二醛、可滴定酸、可溶性固形物、失重率、腐烂率、硬度以及感官品质,来研究茶多酚的保鲜效果。在贮藏期内,圣女果经茶多酚保鲜液涂膜后抗坏血酸、可滴定酸和可溶性固形物下降速率减慢,降低了腐烂率和失重率,表明茶多酚对圣女果的确具有保鲜作用。贮藏至第5 d时,测得的数据均表明涂膜浓度为30mg/L的处理组对所有生理生化指标保持效果最好。此外,对抗坏血酸、丙二醛、失重率、可溶性固形物、硬度以及感官品质保鲜效果最差的是涂膜浓度为50 mg/L的处理组,与30 mg/L的处理组相比两者差异性显著(P <0.05);涂膜浓度为20 mg/L的处理组对可滴定酸和腐烂率的保鲜效果最差,与30 mg/L的处理组相比两者差异性显著(P <0.05)。     

CMC和川陈皮素复合涂膜对青椒保鲜效果的影响

以川陈皮素为成膜材料,添加天然大分子成膜物CMC来制备青椒复合涂膜保鲜剂。研究所制成的涂膜保鲜剂在室温条件下对青椒贮藏品质的影响,以硬度、可溶性固形物含量、呼吸强度、失重率、Vc、叶绿素、多酚氧化酶、丙二醛为指标每隔4 d取样测定,结果表明,CMC和川陈皮素复合涂膜保鲜剂能明显降低青椒在贮藏期间的呼吸强度和失重率,减少Vc和叶绿素的损失,控制丙二醛的增加,抑制腐烂的发生。其中,0.4 g/L的川陈皮素溶液中加入2.0 g CMC制得的涂膜保鲜剂效果最好。     

涂膜保鲜剂中添加茶多酚对草莓贮藏品质的影响

分析廉价成膜材料大豆分离蛋白与天然抑菌抗氧化物质茶多酚对草莓进行涂膜保鲜的可行性.将茶多酚加入成膜剂中,测定贮藏过程中草莓有机酸、维生素C、可溶性固形物等各项指标的变化.结果表明,涂膜剂中添加茶多酚可明显降低草莓果实的失重率,延缓果实维生素C、有机酸和可溶性固形物含量的下降.涂膜保鲜剂中添加茶多酚量为0.3％保鲜效果最佳,果实的贮藏期延长5d.     

不同涂膜保鲜剂对柠檬贮藏品质的影响

以"尤力克"鲜柠檬为原料研究保鲜剂涂膜对其保鲜品质的影响。采用1%壳聚糖、1%魔芋粉和柑橘类专用"科力鲜"涂膜后贮藏于8℃、相对湿度为85%~90%的果蔬冷藏库,定期测定(间隔6 d)柠檬保鲜品质的变化(失重率、可溶性固形物、可滴定酸、Vc、总酚、丙二醛)。结果表明,贮藏30 d后,涂膜组中1%壳聚糖涂膜的柠檬品质最佳,失重率、可溶性固形物、可滴定酸、Vc、丙二醛和总酚含量分别为3.22%、8.51%、5.15 g/kg、23.59 g/100 g、0.71μmol/g、0.72μg/g,1%魔芋粉处理组效果其次,"科力鲜"处理组效果最差。     

涂膜保鲜剂中添加茶多酚对黄花梨贮藏品质的影响

探讨壳聚糖与天然抑菌抗氧化物质茶多酚对黄花梨进行涂膜保鲜的可行性。用茶多酚和壳聚糖混合液处理黄花梨,结合PE保鲜袋包装贮藏,测定贮藏过程中果实呼吸强度、多酚氧化酶(polyphenol oxidase,PPO)活性、VC含量、果实硬度及腐烂率等各项指标的变化。结果表明,壳聚糖联合茶多酚对黄花梨的保鲜效果优于单一保鲜剂,涂膜剂中添加茶多酚可明显抑制多酚氧化酶活性、延缓果实呼吸高峰出现的时间、降低黄花梨的烂果率,VC的保存率高于对照组。涂膜保鲜剂中添加茶多酚量为0.3%时保鲜效果最佳。壳聚糖中添加茶多酚能够明显延长黄花梨的保鲜期。     

茶多酚-川陈皮素-羧甲基纤维素钠复合涂膜剂对刺嫩芽的保鲜效果

利用茶多酚、川陈皮素和羧甲基纤维素钠(Sodium carboxymethyl cellulose,CMC-Na)进行复合涂膜的制备,以刺嫩芽为保鲜对象,以感官评价、失重率、硬度、叶绿素、V_C含量、多酚氧化酶活性和丙二醛含量为指标,多方面评定复合涂膜对刺嫩芽的保鲜效果,并分析了可能的保鲜机理。结果表明:复合涂膜组对刺嫩芽的保鲜效果明显优于对照组,同时也明显优于茶多酚涂膜组和川陈皮素涂膜组。复合涂膜剂可有效地抑制刺嫩芽菜体褐变,维持多酚氧化酶和丙二醛处于较低水平,保持菜体组织形态,保证较高的感官品质,延缓其V_C含量和水分的损失。贮藏12 d时,与对照组相比,复合涂膜处理的刺嫩芽V_C含量提高1.4倍,失重率减少31%,综合各保鲜指标分析,复合涂膜可以延长刺嫩芽4~5 d的贮藏时间。     

库尔勒香梨的生物涂膜保鲜研究

本试验以羧甲基纤维素可食性膜作为生仿酵母菌的载体，研究生物涂膜剂对库尔勒香梨贮藏生理及效果的影响，以期研究出一种天然、无毒、高效的生物涂被保鲜剂。结果表明：涂被保鲜剂处理库尔勒香梨，抑制了果实的呼吸强度、叶绿素分解、PPO活性和MDA的积累，降低果实的腐烂率，显著延缓了果实的后熟软化。加入生仿酵母CMC Yc-b后，能强化CMC的防腐保鲜作用，明显降低了果实的失重率，有效地抑制了可溶性固形物的降解，保持了果肉硬度，在15℃条件下，贮藏2个月，好果率达95%，处理效果最好。     

海藻酸钠复合涂膜对贡柑保鲜效果的影响

以海藻酸钠、壳聚糖和尼泊金复合酯为涂膜材料,采用不同涂膜液对新鲜贡柑进行涂膜保鲜,通过测定其感官评价、VC含量、失重率、可滴定酸含量、可溶性固形物含量、可溶性糖含量、过氧化酶(POD)活性等指标进行评定。结果表明,经1%海藻酸钠+0.3%尼泊金复合酯涂膜处理过的贡柑保鲜效果最优,贮藏第35天时,其感官评价5.7分、失重率10.111%、可溶性糖含量8.208%、可滴定酸含量0.367%、VC含量31.301 mg/100 g、可溶性固形物含量10.27%、POD活性0.680 U/g,能较好保持其营养成分,延长货架期。     

白酒糟醇溶蛋白复合涂膜液对巨峰葡萄的保鲜效果

以白酒糟醇溶蛋白（prolamin from distiller''s grains,PDG）和壳聚糖为基本成分制备添加乳酸链球菌素（nisin）和抗坏血酸（vitamin C,VC）的复合涂膜液。用此复合涂膜液对巨峰葡萄进行涂膜处理,在25℃条件下贮藏9 d,以外观、失重率、硬度、还原糖含量、可滴定酸含量、可溶性固形物含量和丙二醛含量为检测指标,研究复合涂膜液对葡萄的保鲜效果。结果显示,在25℃条件下贮藏第9天时,PDG复合涂膜组和壳聚糖涂膜组的失重率和还原糖含量均显著小于未涂膜组（P<0.05）,PDG复合涂膜组的失重率、硬度及丙二醛含量等指标均优于壳聚糖涂膜组,表明PDG复合涂膜和壳聚糖涂膜均有利于葡萄的贮藏,且PDG复合涂膜的保鲜效果优于单一壳聚糖涂膜。高含量的疏水性氨基酸残基组成赋予PDG良好的保湿性,增强PDG膜的阻氧性,有利于其发挥保鲜作用。     

茶多酚复合溶液对山楂涂膜保鲜效果的研究

为了延长山楂的货架寿命,减少其在储运过程中水分和营养物质损失。以茶多酚、胶原蛋白、明胶、甘油为主要原料制备复合涂膜保鲜液,对山楂进行涂膜处理。在(20±2)℃、60%的相对湿度条件下贮藏,测定山楂的硬度、维生素C含量、感官品质和失重率等指标变化情况,并评价复合涂膜保鲜液的保鲜效果。结果表明,贮藏20天后,经涂膜处理的山楂失重率低于10%,感官评分可达3分以上,硬度高于2.5×10~5Pa/cm~2,维生素C含量高于90mg/100g,均优于未涂膜组。与对照组相比,其货架期可延长12天。优化的涂膜保鲜液配比为:4.0%胶原蛋白、3.0%明胶、0.2%茶多酚、1.0%甘油。     

百里香酚/海藻酸钠膜对茄梨贮藏品质的影响

采用海藻酸钠(Sodium Alginate,SA,2%(m/v))和百里香酚/海藻酸钠(Thymol/Sodium Alginate,Thy/SA,Thy终浓度为40 mg/L)涂膜分别对茄梨进行处理,于20℃下进行贮藏,以果实硬度、可溶性固形物含量、抗坏血酸含量、可滴定酸含量、丙二醛含量、多酚氧化酶活性等指标来判断茄梨的品质变化。结果表明,Thy/SA涂膜使得茄梨果实的贮藏期由9 d(对照组)延长至18 d,有效延缓了果实硬度、可滴定酸、抗坏血酸和总酚含量的下降,以及可溶性固形物、丙二醛含量、多酚氧化酶和过氧化氢酶活性的上升。由此可见,Thy/SA涂膜可较好地维持贮藏过程中茄梨的果实品质,进而延长了其贮藏期。     

毛茶茶多酚提取工艺优化及其对鲜切苹果品质的影响

以茶多酚的含量为指标,利用响应面试验优化毛茶中茶多酚的最佳提取工艺,用茶多酚含量为0、2、4、8 mg/mL的毛茶提取液浸泡鲜切苹果,从ΔE、失重率、硬度、可滴定酸含量、可溶性固形物及感官评定等方面评价其对鲜切苹果的保鲜效果。实验结果表明,毛茶中提取茶多酚的最佳工艺条件为:提取时间65 min,提取温度55℃,超声频率为65 kHz,该条件下实验所得提取物茶多酚的含量为19.312 mg/g。毛茶茶多酚提取物处理鲜切苹果结果表明,毛茶茶多酚提取物能延缓鲜切苹果失重率及硬度的下降,还能延缓鲜切苹果中可滴定酸及可溶性固形物的含量下降,并且能较好地维持鲜切苹果的感官品质,4 mg/mL的毛茶茶多酚提取物能很好地对鲜切苹果进行保鲜。     

CONTROLLED ATMOSPHERE STORAGE AND EDIBLE COATING EFFECTS ON STORAGE LIFE AND QUALITY OF TOMATOES

Tomatoes at pink stage maturities were coated with Semperfresh^TM edible fruit coating which is composed of sucrose esters of fatty acids, sodium carboxymethyl cellulose and mono-diglycerides of fatty acids. One group of coated and uncoated tomatoes were stored at 23 × 2C under air atmosphere, another group was stored at 12C under air atmosphere and third group was stored at 12C, 93–95% RH in a controlled atmosphere (CA) containing 3% CO₂, 3% O₂ and 94% N₂. Samples of tomatoes were analyzed for firmness, weight loss, titratable acidity, pH, soluble solids, sugars, ascorbic acid and lycopene to examine changes in quality during storage. Semperfresh^TM edible fruit coating was found to be significantly effective at both storage temperatures (23 × 2C and 12C) in air to delay changes in firmness, titratable acidity, pH, soluble solids, sugars, ascorbic acid and lycopene. Semperfresh^TM fruit coating reduced fruit weight loss as compared to fruit without coating but the difference between coated and uncoated tomatoes was not significant. Shelf-life of pink tomatoes was increased 3 days at 23 × 2C and 6 days at 12C in air by coating. CA storage delayed compositional changes in tomatoes significantly as compared to air storage of coated and uncoated tomatoes. CA storage also had a significant potential for reducing weight loss and microbial spoilage. Tomatoes were stored 40 days in CA. Coated and uncoated tomatoes exhibited the same results in CA.     

Alginate coating as carrier of oligofructose and inulin and to maintain the quality of fresh-cut apples

The aim of this study was to apply an edible coating containing prebiotics such as oligofructose and inulin to fresh-cut apple wedges. An assessment of the quality, sensory, polyphenol, and volatile attributes of coated and uncoated fresh-cut apple wedges was also undertaken. Fructan analysis showed that all prebiotics remained stable over the 14-d storage period and an intake of 100 g of apple supplies 1 to 3 g of prebiotics. Browning index, firmness, acidity remained stable throughout the 14 d compared to the control while applying prebiotic coatings resulted in an increase in soluble solids. Sensory and visual assessment indicated acceptable quality of apple wedges coated with prebiotics. HPLC analysis showed that levels of polyphenolic compounds were more stable in coated apple wedges (without prebiotic inclusions) than in uncoated control apples. No difference was found between O(2) and CO(2) headspace concentration of coated and uncoated samples. Significant differences (P < 0.001) were found for headspace volatile production between the samples. Most coated samples showed lower volatile production in the headspace than uncoated samples.     

含茶多酚的壳聚糖涂膜对四季豆贮藏品质和 生理生化特性的影响

目的研究壳聚糖联合茶多酚对四季豆涂膜保鲜的可行性。方法以四季豆为实验材料,采用壳聚糖涂膜(浓度为1.5%)、壳聚糖联合茶多酚复合涂膜(1.5%壳聚糖中添加150 mg/kg茶多酚)2种保鲜方式,研究茶多酚对四季豆贮藏品质和生理生化特性的影响。结果茶多酚联合壳聚糖涂膜的四季豆在贮藏期内叶绿素、维生素C、水分含量的下降速率和纤维素含量的上升速率均低于壳聚糖涂膜组,贮藏品质较好。茶多酚联合壳聚糖涂膜的四季豆体内的过氧化物酶(POD)、超氧化物歧化酶(SOD)、过氧化氢酶(CAT)的活力低于壳聚糖涂膜组,但二者均高于未处理组。结论涂膜处理有利于四季豆的贮藏,涂膜剂中加入茶多酚后保鲜效果更好,和壳聚糖涂膜相比可将四季豆贮藏期延长10 d,和不涂膜组相比可延长20d。     

水杨酸对库尔勒香梨黑头病抑制及贮藏品质的影响

为筛选出对库尔勒香梨黑头病抑菌及贮藏效果好的水杨酸最佳处理浓度,通过不同浓度的水杨酸有伤接种梨果实,用无菌水做对照,在室温(25℃)和冷库温度(2℃)条件下对接种后的梨果实进行贮藏,对库尔勒香梨活体损伤接种黑头病致病菌和不同浓度的水杨酸进行试验,室温(25℃)贮藏28 d,冷库贮藏49 d.每隔7 d观察和测定果实的发...     

EFFECTS of SEMPERFRESH and JONFRESH FRUIT COATINGS ON POSTSTORAGE QUALITY of "SATSUMA" MANDARINS

Mandarins were coated with Semperfresh^TM and Jonfresh^TM edible coatings. the weight gain of mandarins after application of Jonfresh and Semperfresh coatings was 0.8% and 0.6% respectively. Weight loss, respiration rate, ascorbic acid, soluble solids (brix) and acidity changes of coated mandarins were compared with uncoated mandarins during storage at 20C and 40% RH for 4 weeks. Semperfresh^TM and Jonfresh^TM coatings delayed the ripening of mandarins. Both of the coatings were effective to reduce the change of ascorbic acid, soluble solids, titratable acidity and respiration rate. But Jonfresh^TM was determined to be most efficient coating for reduction of weight loss.     

不同保鲜剂处理对水蜜桃贮藏效果的研究

研究不同保鲜处理剂(消毒液、植酸、脱氢醋酸钠)对水蜜桃生理生化变化的影响.在自然条件下,以普通贮藏为对照,对水蜜桃失重率、呼吸强度、硬度、多酚、多酚氧化酶、总酸、可溶性固形物、VC含量进行分析测定,结果表明,经过处理能抑制水蜜桃的呼吸强度,延缓硬度、多酚、总酸、可溶性固形物和VC含量的下降速度,抑制失重率和多酚氧化酶的活性,有利于水蜜桃的保鲜.     

Effect of an Edible Nanomultilayer Coating by Electrostatic Self-Assembly on the Shelf Life of Fresh-Cut Mangoes

This work aims at evaluating the effect of an alginate-chitosan nanomultilayer coating, obtained by electrostatic layer-by-layer self-assembling, in the quality and shelf life of fresh-cut mangoes. Coated and uncoated fresh-cut mangoes were stored under refrigeration (8 °C) for 14 days. The changes in mass loss, titratable acidity, pH, ascorbic acid content, total soluble solids, malondialdehyde content, browning rate, and microbial count were evaluated during storage. At the end of the storage period, lower values of mass loss, pH, malondialdehyde content, browning rate, soluble solids, microorganisms’ proliferation, and higher titratable acidity were observed in the coated mangoes. The nanomultilayer coating did not improve the retention of vitamin C during storage of fresh-cut mangoes. Results suggest that chitosan-alginate nanomultilayer edible coating extends the shelf life of fresh-cut mangoes up to 8 days.     

苹果梨和鸭梨酶促褐变机理的研究

以苹果梨和鸭梨为研究对象。在一定的贮藏期内,通过定期测定梨中ｐＨ值,可溶性固形物,褐变度,总酚和多酚氧化酶活性及其与不同底物的结合能力,分析梨的酶褐变机是,苹果梨和鸭梨在贮藏期间,ｐＨ值和可溶性固形物的含量总体呈下降趋势;多酚类物质的含量和多酚氧化酶的活性呈上升趋势,与贮藏期间的褐变度的升高是一致的,多酚氧化酶与底物结合能力的强弱依次为：没食子酸〉儿茶酚〉绿原酸〉咖啡酸;抗坏血酸和还原糖含量对水果