胶孢炭疽菌株QZ-97a分生孢子货架期及对温度的耐受力

将不同含水量的胶孢炭疽菌婆婆纳专化型菌株QZ 97a分生孢子粉置于4℃和室温下,密闭或开放贮存。结果表明,4℃下密闭贮藏6个月,分生孢子萌发率和芽管长度无明显降低,室温贮藏降低也不明显。贮藏10个月后,各种贮藏方式孢子的活力都显著下降。但以4℃、含水量4%、密闭贮藏孢子活力较为稳定,420d孢子萌发率为70 4%,芽管长度为贮藏60d时的43 2%。含水量9 6%、开放室温下贮藏的孢子粉活力下降最大。因此,温度和孢子粉含水量是影响孢子货架期的两个主要因素。分生孢子粉对温度有一定的耐受性,随温度增高,敏感性增强,60℃下分生孢子的活力下降显著,处理6min,孢子芽管长度较对照下降50%。     

果实生长期用MeJA处理对‘红贵妃’芒果货架品质的影响

我国芒果产区因缺乏采后处理条件，致使芒果在货架期品质劣变严重。本文研究了在果实生长期喷施茉莉酸甲酯（MeJA）对‘红贵妃’芒果采后品质的影响。结果表明：与对照相比，5 mg/L的MeJA处理显著降低了芒果货架期的病情指数和发病率、延缓了果皮转黄、提高了果肉的TSS和Vc含量、降低了TA含量，使芒果在货架期保持较好的外观和营养品质。同时，MeJA处理抑制了采后炭疽病的发生，在货架前期降低了CAT和POD活性，提高了总酚、总黄酮、H2O2含量，在货架后期提高了CAT和POD活性，降低了H2O2含量。本研究表明，生长期MeJA处理使芒果保持较好货架期品质与其增强果实在货架期的抗病性有关。     

气调包装复合保鲜技术在水产品保鲜中的应用现状

水产品营养价值高,含有多种氨基酸、不饱和脂肪酸、矿物质等营养素而脂肪含量相对较低,深受人们喜爱,也是中国居民膳食指南中的重要组成部分。水产品中由于水分、蛋白质等成分含量丰富,极易在微生物和内源酶的作用下发生蛋白质、脂肪等的降解或氧化而腐败变质,从而缩短了货架期,降低了商业价值。气调包装保鲜技术是指通过使用高阻隔性能的复合包装材料,并调整食品贮藏环境中的气体组成来改善食品贮藏品质并延长货架期的技术,因其安全性高、保鲜效果好而被广泛应用于水产品保鲜领域中,本文总结了近几年气调包装复合其他保鲜技术(低温、紫外杀菌、臭氧处理、超高压处理、化学保鲜剂、生物保鲜剂)在水产品保鲜领域中的应用,旨在为气调包装在水产品保鲜中的进一步应用提供理论依据。已有的研究表明该复合技术能有效地降低水产品贮藏末期微生物总数、挥发性盐基氮、三甲胺、生物胺等指标,并维持较高的感官评分、水分含量、鲜度值,可有效延长水产品的货架期,未来可以从气调包装复合保鲜技术的抑菌机理、理化指标变化机理、包装材料及模式等方面展开深入研究。     

Shelf-Life of Spanish Mackerel (Scomberomorus commerson) from Northern Australian Waters

Abstract

The shelf-life of Spanish mackerel caught by line fishing in Northern Australian waters was evaluated. Spiked fish were stored in ice either headed and gutted or left uncut and subjected to sensory, nucleotide, pH, histamine and microbial analysts and the rigor pattern recorded. There was little difference between the two product forms. Rigor in uncut fish lasted for 14 ± 9.8 hours and in headed and gutted fish for 19.6 ± 16.3 hours. Spanish mackerel retained good sensory quality for up to 14 days. The bacterial load reached 105 cfu/g by 18 days. K values were low for most of the storage time, < 40%. Histamine levels did not develop more than 10 mg/kg during storage. The pH of Spanish mackerel did not change much even though bacterial levels become high.     

高CO2和纯N2冲击处理对板栗货架期品质变化的影响

以‘燕昌’板栗为试材,研究了经180d冷藏的板栗出库前分别用50％CO2和纯N2冲击处理对板栗货架期品质的影响。结果表明：50％CO2和纯N2处理对板栗货架期内糖代谢有显著影响,对蛋白质代谢影响不大。50％CO2处理5d以及纯N2处理5d和10d有利于板栗淀粉的保存。50％CO2处理可明显降低板栗的发芽率和腐烂率,货架期结束时,冲击处理5d和10d的板栗发芽率分别为2．07％和3．65％,显著低于对照(18．06％),腐烂率均为2．67％,显著低于对照(5．33％),而纯N2处理则显著促进板栗发芽,且不能有效控制腐烂的发生。研究证明：50％CO2冲击处理5d既能使板栗保持较好的货架期品质,又能显著抑制发芽及腐烂。     

冷鲜肉微生物种类及微生物预测模型的研究进展

肉品安全是一个重要的研究课题,预测肉品微生物的变化是监测食品货架期的基础,它根据食品微生物在不同加工技术、储藏和流通条件下的变化规律,通过建立模型和计算机处理,判断食品内主要致病菌和腐败菌生长或残存的动态变化,从而对食品的质量和安全性作出快速评估和预测。生鲜肉食品的腐败主要是生产加工过程中微生物污染所致,不同的微生物在特定的条件下生长速率不同,因此不同冷鲜肉类上的特定腐败菌也有所不同。根据微生物在特定的肉类以及环境条件下的生长规律构建微生物预测模型,从而进行货架期预测。综述各种冷鲜肉上的腐败菌以及当前的微生物预测模型种类,并展望该领域的发展方向。     

壳聚糖对草莓冷藏和货架期间品质的影响

以"达赛莱克特"草莓为试材,研究1%壳聚糖处理的草莓果实在0℃低温贮藏7 d后20℃常温货架6 d期间的品质变化规律。结果表明:与对照(0.1%醋酸溶液处理)相比,壳聚糖处理降低了低温贮藏后期和货架期草莓果实的呼吸速率、花青素、类黄酮及酚类物质的含量,保持较高的果实硬度,显著减少了货架期草莓果实腐烂和霉菌的发生,对果实失重率和可溶性固形物含量无显著影响。表明1%壳聚糖处理可有效延缓草莓的采后衰老进程,延长果实的货架期。     

The potential of ripening mutants for extending the storage life of the tomato fruit

Summary The effect of the fruit ripening mutants rin, gr, nor and Nr on storage life and pigmentation was investigated in homozygous material, in heterozygous F₁ combinations between the mutants with the colour mutant hp and with the normal cv. Kewalo. Crosses with nor showed a 3-to 5-fold increase in storage life in comparison with the normal cv. or with hp. Maximum pigmentation of the fruits of crosses with nor was pale-red with vineripened fruit and pink with fruit harvested at the breaker stage and ripened on the shelf. The ripening inhibitory effect of rin in the different F₁ combinations was less pronounced than that of nor, and the colour of the fruits was improved. Fruits of the F₁ cross between rin and nor showed greatly improved storage life and developed pink or pale red colour. Most heterozygotes with hp showed improved pigmentation. Problems anticipated in utilizing ripening mutants in breeding for improved keeping quality are discussed.     

Characterization of six varieties of Cucumis melo L. based on morphological and physiological characters, including shelf-life of fruit

Seventy-two accessions covering six varieties of Cucumis melo were characterized by using 35 morphological characters with emphasis on shelf-life, and the relationships between shelf-life and related characters was investigated. Principal component analysis (PCA) revealed that development period of plant and fruit, size of seed and fruit, shelf-life, stem hair, flesh juiciness, netting, abscission of peduncle, rapid yellowing of epidermis at maturity, Brix value, and color of flesh and epidermis etc. were the principal characters to discriminate melon accessions examined in the present study. According to the scatter diagram, vars. acidulusand makuwa, both of which belong to the Oriental melon, are closely related because of their short growth duration, small seed, thin pericarp and poor shelf-life, while American cantaloupe (var.reticulatus) and European cantaloupe (var. cantalupensis) are rather closely related due to their climacteric fruit with orange flesh, slipped peduncle and rapid yellowing of epidermis at maturity, which is closely related with their shelf-life. PCA also indicated that var. saccharinus was closer to var. inodorus than to the other varieties, due to their requirement of long period for development, large size of seed and fruit, and half- or non-slipped peduncle. Shelf-life of melon fruit was significantly correlated with the following characters: quality of flesh, size of seed and fruit, abscission of peduncle, development periods of plant and fruit, rapid yellowing of epidermis at maturity, Brix value and color of flesh and epidermis. Accessions with good shelf-life were mostly found in vars. saccharinus and inodorus. This revised version was published online in July 2006 with corrections to the Cover Date.     

超高温灭菌乳货架期品质稳定性变化研究

研究了超高温灭菌乳货架期理化特性的变化,为提高其货架期品质稳定性提供理论基础。取贮存1～6月UHT牛乳,测定上下层乳脂肪、蛋白质、总固形物含量及流变学特性。结果表明,3个月后UHT乳脂肪上浮量显著增加(p<0.05);4个月货架期后蛋白质下沉量显著增大(p<0.05);6个月货架期后上下层乳液总固形物含量无显著差异(p>0.05);6个月货架期后上层乳液的黏度高于下层乳液。超高温灭菌乳货架期3个月后发生脂肪上浮、蛋白质和总固形物下沉、上下层黏度不均一现象。