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1.
Optimising packaging for minimally processed 'Barattiere' melon cultivar ( Cucumis melo L.) is addressed in this work. Melon slices were dipped in water solution containing ascorbic acid (1%) and calcium chloride (0.2%). Dipped and untreated fresh-cut produce was packaged in four different polymeric materials (two biodegradable films, a commercially available multilayer film (MLF) and polypropylene), before storing at 5 °C. During storage, headspace gas composition, microbial quality, pH and mass loss were monitored for a period of 2 weeks. Results suggest that film characteristics strongly influenced gas concentrations in the headspace, microbial growth and weight. Among the tested packaging materials, the MLF seemed to delay significantly the detrimental phenomena involved in quality acceptance, even if clearly anaerobic atmospheres were recorded. The biodegradable films, combined with a dipping pre-treatment, could represent a good compromise between film performance and environmental impact.  相似文献   

2.
Seeds from a melon hybrid ‘ChunLi’ were analysed for their proximate composition. The seeds contained high percentages of lipids (35.36%) and proteins (29.90%). Hexane‐extracted oil had acid, peroxide, iodine and saponification values of 1.51, 3.95, 89.5 and 226.73, respectively. Gas chromatographic analysis of the oil revealed the presence of twenty‐five fatty acids varying from C4 to C24 with the exception of C5, C7, C11 and C19. The concentrations of individual fatty acids varied from trace quantities to about 54.8%. Linoleic, oleic, palmitic and stearic acids were the principal fatty acids contributing to 53.9%, 12.1%, 23.9% and 5.7%, respectively, of the total fatty acids which had a relatively high percentage (67.5%) of unsaturated fatty acids. Seed proteins were rich in arginine, aspartic and glutamic acids while limiting amino acids were methionine and lysine.  相似文献   

3.
不同超高压处理压力对哈密瓜汁香气的影响   总被引:11,自引:1,他引:11  
采用固相微萃取方法对不同超高压处理的哈密瓜汁的香气进行富集 ,并经GC MS联机检索分析 ,发现超高压处理对哈密瓜汁中的酯类、醇类、醛类和酮类都有影响 ,其中超高压处理哈密瓜汁的酯类减少了 5种且峰面积减少了约 10 % ,而醛类和酮类增加。 5 0 0MPa/2 0min处理的哈密瓜汁与 40 0MPa/2 0min处理的哈密瓜汁相比 ,酯的种类和峰面积变化不大 ,酮的种类没有变化 ,但增加了 3种不饱和醛。 2种超高压条件处理的哈密瓜汁酯类的特征香气成分未变 ,但醇类和醛类的特征香气成分变化较大。感官评定表明 :超高压处理的哈密瓜汁的香气减弱 ,青鲜气增强 ,这与哈密瓜汁香气成分检测的结果相符合。  相似文献   

4.
甜瓜发酵饮料的研究   总被引:1,自引:0,他引:1  
以甜瓜为原料,研究具有甜瓜特殊风味的乳酸菌发酵饮料.采用驯化的保加利亚乳杆菌和嗜热链球菌(1:1)为发酵菌种,通过正交试验确定最佳发酵条件为:白砂糖4%,奶粉5%,发酵温度42℃,接种量4%,发酵时间48h.稳定剂选用CMC+黄原胶1:1混合,用量为0.2%.研制的产品口感细腻酸味可口,风味独特,是营养保健型发酵饮品.  相似文献   

5.
6.
不同贮藏温度对采后86-1哈密瓜果实冷害及品质的影响   总被引:1,自引:0,他引:1  
为了研究不同贮藏温度对采后哈密瓜果实冷害及品质的影响,分别对1、3、5℃贮藏条件下86-1哈密瓜果实的冷害症状、冷害指数、冷害率、细胞膜相对透性、硬度、可溶性固形物含量、可滴定酸及维生素C含量进行了系统观察、统计与测定。结果表明:86-1哈密瓜冷害的发生与贮藏温度及持续时间有关,1℃贮藏条件下,86-1哈密瓜果实冷害出现的时间较早,果实的冷害指数、冷害率及细胞膜相对透性较高;硬度、可溶性固形物及维生素C含量下降较快,可滴定酸出现先上升后下降的趋势。3℃贮藏有利于维持86-1哈密瓜果实的品质,5℃贮藏果实虽未发生冷害,但后期品质劣变较快,腐烂较重。  相似文献   

7.
8.
The influence of alcoholic and malolactic fermentations on the levels of amines in Merlot wines was investigated. Saccharomyces bayanus, S. cerevisiae, Lactobacillus plantarum, Oenococcus oeni (DSM 7008 and 12923) and spontaneous fermentations were used. Four of the 10 amines investigated were detected: spermidine, serotonin, putrescine and cadaverine. When considering the factors independently, the malolactic bacteria significantly affected the levels of serotonin and total amines, whereas the fermentation yeasts significantly affected the levels of spermidine (two way Kruskal–Wallis, p ? 0.05). Spermidine levels were significantly higher in wines produced with S. cerevisiae. Significantly higher serotonin levels were found in wines made with L. plantarum. Putrescine and cadaverine were not detected in wines produced by spontaneous alcoholic fermentation or by L. plantarum. There were significant differences in alcohol content, total and volatile acidity, sulphite levels and taste quality among wines (Tukey test, p ? 0.05).  相似文献   

9.
The aim of the research was to assess the possibility of the fermentation productivity rising through the increase in corn mashes extract from 16–17 to 20–21°Balling, yet keeping a 3-day fermentation period. The second goal was to obtain the highest possible utilization of starch in the raw material through deep enzymatic degradation and utilization of available sugars and simultaneous maintenance of high quality spirit. It was found that fulfilling the above during the 3-day fermentation period was possible with the application of pullulanase as an additional amylolytic enzyme. Adding pullulanase resulted in the acceleration of the starch hydrolysis degree, which led to lower amounts of unhydrolyzed dextrins and higher ethanol yield. When the supportive enzymes complex (pullulanase, protease and cellulase) was used, the final ethanol concentration reached 10.86 ± 0.04% v/v, with ethanol yield at 68.41 ± 0.23 dm3 of absolute ethanol (A100) per 100 kg of starch, which was 95.25 ± 0.32% at the theoretical value. The acceleration of starch enzymatic degradation and the application of a proteolytic preparation visibly shortened both initial and main fermentation phases. This in turn increased the time of the final fermentation phase and resulted in more extensive utilization of substrates by yeasts with simultaneous reduction of the final concentration of acetaldehyde (26.0 ± 0.5 mg/dm3A100) and diethyl acetal of acetaldehyde (2.5 ± 0.5 mg/dm3A100). The quality of spirit obtained was positively verified also in terms of relatively low concentration of higher alcohol (3912.2 ± 9.8 mg/dm3A100). Preliminary analysis of costs (without raw-material) of 1 l distillate production indicated the possibility to reduce the costs by 18–20%.  相似文献   

10.
Benzo (1, 2, 3)-thiadiazole-7-carbothioic acid S-methyl ester (BTH) is a novel synthetic elicitor capable of inducing disease resistance in many plants. Fruits were dipped in BTH at 100?mg/L for 10?min, and then stored at room temperature (22?±?2?°C, relative humidity 55–60?%). The results showed that BTH significantly (P?<?0.05) reduced the lesion area of fruits inoculated with Trichothecium roseum and the natural disease incidence of fruits during storage at room temperature. The treatment effectively maintained cell membrane integrity and decreased the production of lipid peroxidation and malondialdehyde. BTH treatment markedly enhanced the accumulation of hydrogen peroxide, (H2O2) while decreased the rate of superoxide anion (O 2 ·? ) production. Furthermore, BTH observably increased the activities of NADPH oxidase (NOX, EC1.6.3.1), superoxide dismutase (SOD, EC1.15.1.1), peroxidase (POD, EC1.11.1.7), ascorbate peroxidase (APX, EC1.11.1.11), and glutathione reductase (GR, EC1.6.4.2), while inhibited the catalase (CAT, EC1.11.1.6) activity. These results indicated that BTH treatment increased the disease resistance of muskmelon fruits by enhancing their antioxidant system activity after harvest, and suggested that postharvest treatment with BTH could be promising in reducing decay and reducing or/and substituting chemical fungicides to control postharvest diseases in fruits.  相似文献   

11.
Silicon oxide and sodium silicate were investigated as potential agents for the control of postharvest pink rot in Chinese cantaloupe (cultivar Yujingxing) caused by Trichothecium roseum. In vitro tests showed that sodium silicate, when added to potato dextrose agar, was effective in suppressing the radial growth of the pathogen on the medium, whereas silicon oxide was ineffective. The effectiveness of sodium silicate increased with concentration, and the growth of the fungus was completely inhibited at 100 mm . When melons were dipped in the solutions, both silicon oxide and sodium silicate significantly (P < 0.01) reduced the severity of pink rot of the cantaloupe with lesion diameters reduced by up to fivefold when compared with the controls. Scanning electron microscopy‐energy dispersive X‐ray analysis showed that silicon (Si)‐treated melons had a smoother surface feature and higher Si levels in the epidermis, especially at the stomata and along the junction between the exocarp and mesocarp. Enhanced peroxidase and phenylalanine ammonia lyase activities were observed in sodium‐silicate‐treated melons but not in those treated with silicon oxide. The results indicate that different mechanisms might be involved in sodium silicate and silicon‐oxide‐initiated reduction of postharvest pink rot in Chinese cantaloupe.  相似文献   

12.
M.R. Pérez-Gregorio 《LWT》2011,44(8):1793-1801
The aim of the present study was to evaluate the profile of the phenolic constituents of Morus nigra fruits and their antioxidant activity (DPPH) and to compare their contents before and after fermentation. Antioxidant phenolics of black mulberry (M. nigra L.) samples grown in Galicia (NW Spain) were extracted with methanol/formic acid/water (MFW) and determined by high performance liquid chromatography (HPLC). Two major anthocyanins (cyanidin 3-glucoside and cyanidin 3-rutinoside) and two flavonols (quercetin 3-glucoside and rutin) were isolated, together with caffeic acid and other hydroxycinnamic and ellagic acid derivatives. Their chemical structures were identified by spectral analyses with diode array detection (DAD), but also with alkaline saponification and acid hydrolysis of the mulberry phenolics. Good correlations (r2 = 0.6229) were observed among total flavonols contents and the IC50 radical scavenging capacities of mulberry fruits. Anthocyanins are the major flavonoids present in mulberry. It would be expected that anthocyanins contribute significantly to their antioxidant activity; nevertheless, alcohol generated during fermentation may also contribute to antioxidant activity. Our results provide useful antioxidant nutritional information of fresh and fermented mulberry fruits.  相似文献   

13.
Analytical data on fatty acid, amino acid and mineral content of defatted melon seed and fluted pumpkin seed are presented and discussed. Also discussed are experimental data on availability of amino acids and minerals in these meals. Defatted melon seed and fluted pumpkin seed have protein contents of 66.20% and 66.54%, respectively, with an excellent pattern of amino acids, containing higher levels of most essential amino acids (except lysine) than soya bean meal. Amino acid availability is high (melon seed 95.30%, pumpkin seed 93.12%) and similar to the level in soya bean meal (94.31%). Mineral availability is significantly lower in melon seed (53.63%) and soya bean meal (54.94%) than in pumpkin seed (58.84%). The potential for increased dietary utilisation of melon and fluted pumpkin meals and flours to meet the dietary needs of monogastric animals as well as human subjects is discussed.  相似文献   

14.
This research determines the concentrations of various phthalates in French wines and grape spirits marketed in Europe or intended for export. Dibutyl phthalate (DBP), diethylhexyl phthalate (DEHP) and butyl benzyl phthalate (BBP) were the most frequently detected compounds in the wines analysed. While only 15% of the samples examined contained quantifiable concentrations (> 0.010 mg kg–1) of DEHP and BBP, 59% of the wines contained significant quantities of DBP, with a median value as high as 0.0587 mg kg–1. Only 17% of the samples did not contain any detectable quantity of at least one of the phthalates and 19% contained only non-quantifiable traces. In the spirits analysed, DBP (median = 0.105 mg kg–1) and DEHP (median = 0.353 mg kg–1) were the substances measured at the highest concentrations, as well as the most frequently detected (90% of samples). BBP was present in 40% of the samples at an average concentration of 0.026 mg kg–1. Di-isobutyl phthalate (DiBP), which is not permitted in contact with food, was found in 25% of the spirits tested. According to the specific migration limits (SML) for materials in contact with food, slightly more than 11% of the wines analysed were non-compliant, as they exceeded the SML for DBP (0.3 mg kg–1); just under 4% were close to the SML for DEHP. Concerning spirits, 19% of the samples analysed were considered non-compliant to the SML for DBP and nearly 7% were close to the SML for DEHP. The aged grape spirits analysed were often excessively contaminated with DiBP, which is not permitted to be used in contact with food (> 0.01 mg kg–1). A study of various materials frequently present in wineries revealed that a relatively large number of polymers sometimes contained high concentrations of phthalates. However, the epoxy resin coatings used on vats represented the major source of contamination.  相似文献   

15.
Bifidobacterium adolescentis Int57 (Int57) and Propionibacterium freudenreichii subsp. shermanii ATCC 13673 (ATCC 13673) were grown either in coculture or as pure cultures in different media, such as cow's milk, soybean milk, and modified MRS medium. The viable cell counts of bacteria, changes in pH, concentrations of organic acids, and contents of various sugars were analyzed during incubation up to 7days. In soy milk, the survival of cocultured Int57 was six times higher than the monocultured cells, and ATCC 13673 cocultured with Int57 consumed 69.4% of lactic acid produced by Int57 at the end of fermentation. In cow's milk, coculture with ATCC 13673 increased the growth of Int57 from 24h until 120h by approximately tenfold and did not affect the survival of Int57 cells. After 96h of fermentation of modified MRS, the survival of ATCC 13673 cells cocultured with Int57 increased by 3.2- to 7.4-folds as compared with ATCC 13673 monoculture, whereas the growth of Int57 cells was unaffected. The growth and metabolic patterns of two strains during coculture showed noticeable differences between food grade media and laboratory media. The consumption of stachyose in soy milk during coculture of Int57 with ATCC 13673 was increased by more than twice compared with Int57 monoculture, and completed within 24h. The combinational use of Bifidobacterium and Propionibacterium could be applied to the development of fermented milk or soy milk products.  相似文献   

16.
为提高哈密瓜幼果的综合利用价值,拓宽泡菜种类,采用5种不同发酵方式制得哈密瓜幼果泡菜,在测定发酵过程中的pH、质构、总酸、亚硝酸盐、盐度和感官品质的基础上,采用全自动氨基酸分析仪对原料、泡菜发酵中点和终点泡菜的氨基酸含量进行测定,通过氨基酸比值系数法进行营养评价.结果表明:发酵终点时,5种发酵方式发酵的泡菜pH均在3....  相似文献   

17.
The aim of the present study was to obtain two distilled alcoholic beverages from red raspberry and arbutus berry by solid-state fermentation and subsequent distillation of the fermented fruits. The mean concentrations of ethanol and volatile substances in the distillates from red raspberry (41.3 and 200.1 g/hL aa) and arbutus berry (44.3 and 267.1 g/hL aa) were higher than the corresponding minimum limits (38.5 and 200 g/hL aa) fixed by the European Council (Regulation 110/2008) for fruit distillates. In addition, the mean concentrations of methanol in the two alcoholic beverages (113.9 g/hL aa in case of red raspberry, and 320.5 g/hL aa in case of arbutus berry) were much lower than the maximum levels of acceptability that the aforementioned regulation fixed for red raspberry (1200 g/hL aa) and arbutus berry (1000 g/hL aa) distillates. These results showed that both fruits can be used as fermentation substrates for producing two alcoholic beverages with high quality, which are safe for the consumers without any repercussion to their health from methanol concentrations.  相似文献   

18.
为优化苦瓜中皂苷的提取条件及其抗氧化活性,以皂苷得率为考察指标,研究了提取温度、时间、乙醇浓度和料液比对苦瓜皂苷提取的影响,并采用正交试验确定最佳条件;以苦瓜皂苷对超氧自由基、羟基自由基的清除率作为考查指标,研究苦瓜皂苷的体外抗氧化活性。确定了最佳提取工艺条件为:最佳提取乙醇浓度为70%,料液比为1:15,温度55℃,提取时间2.5h。0.4mg/mL苦瓜皂苷对超氧自由基的清除率达到92.5%,对羟基自由基(·OH)的清除率达到78.9%  相似文献   

19.
The effects of 1-methylcyclopropene (1-MCP) on quality and cell wall hydrolases activities changes in fresh-cut muskmelon fruit stored at 4?±?1 °C for 7 days were investigated. The results showed that ethylene production of the fresh-cut fruit remained constant during refrigerated storage. 1-MCP treatments delayed the loss of fresh weight and the increase in electrolyte leakage and maintained the firmness of the fresh-cut fruit. The best results are showed in the fresh-cut fruit treated with 1.0 μL L?1 1-MCP. The use of 1-MCP had no influence on the total soluble solids (TSS) content and pH of the fresh-cut fruit which they remained constant over storage. The titratable acidity (TA) of the fresh-cut fruit decreased during storage and the sample treated with 1.0 μL L?1 1-MCP showed the lowest data. TSS/TA ratio increased during storage and the TSS/TA ratio was lower in 1-MCP-treated samples than that for the control one. The use of 1-MCP inhibited polygalacturonase (PG), β-galactosidase (β-Gal) and β-galactanase activities, whereas the increases in these enzymes activities were found in the control. Antioxidant capacity and total phenolics content of both 1-MCP-treated and untreated samples remained constant over storage. The reduction of total ascorbic acid content was detected after 7 days of storage. The ascorbic acid content in 1-MCP-treated sample was slightly higher, although not significantly different, than that of the control after 7 days. These results suggest that the loss of firmness was the key factor affecting quality of fresh-cut muskmelon fruit and the use of 1-MCP maintained the quality and inhibited the loss of firmness by retarding the increase in electrolyte leakage and inhibiting cell wall hydrolases activities.  相似文献   

20.
This research were study physical and chemical changes of fresh-cut melon and papaya on different storage and shelf-life evaluation of products. Fresh-cut melon and papaya was kept at the different storage temperature conditions with observed on physical characteristics of texture and color of their flesh and measured of chemical characteristics on water content, sucrose content, acidity, vitamin C, and total carotene. Physical and chemical changes were observed on fresh-cut melon and papaya under different storage conditions.Fresh-cut products stored in lower temperature on ±14-15 °C had optimum shelf-life of 4 days for melon and 3 days for papaya.  相似文献   

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