Shelf Life of Minimally Processed Honeydew, Kiwifruit, Papaya, Pineapple and Cantaloupe

This study was to determine the shelf life of minimally processed honeydew melon, kiwifruit, papaya, pineapple, and cantaloupe stored at 4°C. Sensory assessments were carried out at 3-day intervals by highly trained panels until the end of shelf life. Microbiological counts were made immediately after dicing fruit and at the end of shelf life. Results indicated that both the length of shelf life and type of spoilage were related to fruit species. Minimally processed fruit had longer shelf life at 4°than at temperatures recommended for whole fruit when these were greater than 4°C. Spoilage of 4°C-stored kiwifruit, papaya and pineapple pieces was not a consequence of microbial growth.     

Green and gold kiwifruit peel ethanol extracts potentiate pentobarbital-induced sleep in mice via a GABAergic mechanism

Kiwifruit is one of the most popular fruits worldwide, and it has various biological properties, including antioxidant, anti-allergic, and cardiovascular protective effects. The peel of kiwifruit, which is a by-product of processing, is a good source of flavonoids; however, its bioactivity has not been widely investigated. In this study, we evaluated the hypnotic effects of green (GRPE, Actinidia deliciosa) and gold (GOPE, Actinidia chinensis) kiwifruit peel ethanol extracts and their solvent fractions, and the possible underlying mechanisms. Oral GRPE and GOPE administration (125–1000 mg/kg) produced a dose-dependent decrease in sleep latency and an increase in sleep duration in pentobarbital-treated mice. Among three different solvent fractions of GRPE and GOPE, ethyl acetate (EA) fractions had the greatest effect on sleep duration at 250 mg/kg. The total flavonoid contents of solvent fractions were proportional to sleep duration. Like diazepam (a GABA_A–benzodiazepine (BZD) receptor agonist), the hypnotic effects of GRPE, GOPE, and their EA fractions were fully inhibited by flumazenil (a GABA_A–BZD receptor antagonist). These results suggest that potentiation effects of GRPE and GOPE on pentobarbital-induced sleep in mice may be modulated by a GABAergic mechanism.     

猕猴桃澄清果汁加工工艺研究

利用壳聚糖聚阳离子电解质的特性澄清猕猴桃汁,选择壳聚糖脱乙酰度、壳聚糖加入量、果汁pH、加入壳聚糖后47℃果汁保温时间与澄清果汁的透光率的关系进行单因素实验,并在单因素实验基础上用拟因子正交实验设计,找出了澄清猕猴桃原汁的最优条件为:用脱乙酰度80%的壳聚糖,加入量为0.4g/L,加入壳聚糖后果汁于40℃保温40min,果汁pH为自然pH值,壳聚糖澄清猕猴桃汁之后离心时间为30min;影响澄清猕猴桃汁的显著因素为壳聚糖的脱乙酰度、加入壳聚糖后果汁的保温时间和离心时间。     

猕猴桃果醋的工艺研究及其成分分析

研究了猕猴桃果醋的生产工艺，并分析了猕猴桃果醋中的氨基酸含量、相对分子质量分布及VC含量等，结果表明：酒精发酵的最侍条件是在25℃的条件下添加果洒酵母和酒精酵母混合发酵，其配比为2：1，接种量10％。醋酸发酵的最传条件是温度33℃，最初酒精度5．0％，初始pH值为55，醋酸菌接种量12％。     

响应曲面法优化猕猴桃酒酵母培养条件

利用JMP和Box-Behnken响应曲面设计(RSM),研究了培养条件对猕猴桃酒酵母WF25增殖作用的影响。研究结果表明:温度、装液量、转速、初始pH和培养时间对猕猴桃酒酵母WF25细胞的增殖均有极显著的影响。当培养条件为温度28.5℃、初始pH4.5、转速175r/min、装液量65mL和时间30h时,生物量的预测值可达3.06352×108个/mL。     

基于siPLS的猕猴桃糖度近红外光谱检测

为了探寻一种快速无损检测猕猴桃糖度的方法,利用小波滤噪法对猕猴桃1000～2500nm 近红外光谱进行了预处理,并用偏最小二乘法(PLS)、区间偏最小二乘法(iPLS)和联合区间偏最小二乘法(siPLS)分别建立预测模型。结果表明,采用联合区间偏最小二乘法将光谱划分为16 个子区间,利用其中的第9、11、13 号3 个子区间联合建立的糖度模型效果最佳,其校正集相关系数和均方根误差分别为0.9414 和0.3788。预测集相关系数和均方根误差分别为0.9295 和0.3904,主因子数为7 个。研究表明,用小波滤噪和联合区间偏最小二乘法所建立的猕猴桃糖度模型不但减少建模运算时间,剔除噪声过大的谱区,而且预测能力和精度均有所提高。     

采前氯吡脲处理对‘秦美’猕猴桃贮藏期间果实硬度及细胞壁降解的影响

以‘秦美’猕猴桃果实为试材,于盛花期后28 d分别采用0（对照,清水）、5、10、20 mg/L 4 个质量浓度的氯吡脲（1-(2-chloropyridin-4-yl)-3-phenylurea,CPPU）溶液进行蘸果处理,蘸果时间3～5 s,研究采前CPPU处理对‘秦美’猕猴桃贮藏期间果实硬度及细胞壁降解酶活力的影响。结果表明：CPPU处理加速了果实硬度、原果胶和纤维素质量分数的下降,提高了可溶性果胶质量分数及多聚半乳糖醛酸酶（polygalacturonase,PG）、果胶甲酯酶（pectin methylesterase,PME）、纤维素酶（cellulase,Cx）和β-半乳糖苷酶（β-D-galaetosidase,β-Gal）细胞壁降解活力。各处理组果实硬度与可溶性果胶质量分数和PG、Cx活力呈极显著负相关（P＜0.01）,与原果胶、纤维素质量分数呈极显著正相关（P＜0.01）;20 mg/L CPPU处理组果实的β-Gal活力与硬度呈显著负相关（P＜0.05）。CPPU处理提高了果实细胞壁降解酶的活力,促进了细胞壁的降解,加速了贮藏期间果实的软化,降低了果实的耐贮藏性。为维持猕猴桃采后果实硬度,延长贮藏期,生产中不宜使用CPPU处理,或使用的质量浓度不宜超过5 mg/L。     

采后猕猴桃可溶性固形物含量的高光谱无损检测

为探讨基于高光谱成像技术无损检测采后猕猴桃可溶性固形物含量（soluble solids content,SSC）的可行性,基于猕猴桃900～1 700 nm波长范围的反射高光谱,建立了预测SSC的偏最小二乘、支持向量机及误差反向传播 （error back propagation,BP）网络模型,并综合比较了分别以全光谱的226 个波长,利用连续投影算法提取的12 个有效波长和采用无信息变量消除法提取的128 个有效波长作为模型的输入变量对各模型预测效果的影响。结果表明,连续投影算法能有效地提取有效波长,其在简化模型方面优势明显;BP网络与连续投影算法相结合具有最好的预测性能（预测相关系数为0.924,预测均方根误差为0.766）。研究表明,高光谱成像技术可无损检测猕猴桃的SSC,该技术将使猕猴桃内部品质的工业化分级成为可能。     

野生猕猴桃果酒酵母的筛选鉴定及耐受性的研究

文中主要筛选适合野生猕猴桃果酒发酵的酵母.通过显微镜观察和WL培养基的颜色变化,初筛出酵母菌136株.采用杜氏管发酵法,CO2失重比较法,猕猴桃果汁发酵法等从中复筛出两株发酵能力好、絮凝能力强、产香较好的菌株:YM-7和YM-210,初步鉴定均为酵母属的酿酒酵母.对YM-7菌种进行了耐受性研究,结果表明YM-7对葡萄糖、酒精度、酸度、NaC1和SO2具有较高耐受性,可作为野生猕猴桃发酵专用菌种或选育野生猕猴桃专用菌种的出发菌株.