Quality changes of fish patties produced from anchovy during refrigerated storage

Quality changes of anchovy patties at the storage temperature of 4 °C were investigated. After patties had been prepared using minced anchovy meat they were stored in a refrigerator. Quality control analyses were conducted for every day of storage. Total volatile basic nitrogen and thiobarbutiric acid values increased, and acidity and sensory scores decreased during the storage. The peroxide value significantly increased until the fifth day of storage then decreased on days 5 and 6 of storage. Anchovy patties were consumable up to 6 days.     

1-甲基环丙烯结合茉莉酸甲酯雾化熏蒸对石榴采后品质的影响

目的 探究1-甲基环丙烯(1-methylcycloproene,1-MCP)和茉莉酸甲酯(methyl jasmonate,MeJA)联合处理对石榴贮藏过程生理代谢和病害的协同调控作用。方法 以和田石榴为对象,采用1-MCP结合MeJA雾化熏蒸处理,研究其对冷藏条件下果实品质的影响。结果 1-MCP结合MeJA雾化熏蒸处理有效延缓了石榴果实在冷藏过程中的果皮褐变,较好保持了果实色泽,降低了果实腐烂率,保持了果实可溶性固形物、可滴定酸和总酚含量,抑制多酚氧化酶活性,减缓过氧化物酶、过氧化氢酶和超氧化物歧化酶活性的下降,同时保持较低的丙二醛含量和细胞膜透性。此外,结合处理还能维持较高的果实可溶性蛋白含量并保持良好的果皮微观结构。结论 1-MCP结合100μmol/L MeJA雾化熏蒸处理的石榴贮藏品质最佳,为石榴采后商品化处理提供了依据。     

杀菌方式对卤制风味四角蛤蜊产品贮藏品质的影响

目的 为探究不同杀菌方式对四角蛤蜊卤制风味产品在贮藏期间品质的影响。方法对四角蛤蜊卤制风味产品分别进行超高压杀菌、巴氏杀菌和高温杀菌,并在4 ℃下进行贮藏,对其菌落总数、质构、色差、pH值、硫代巴比妥酸（thiobarbituric acid,TBA)值、感官指标、电子鼻、电子舌和挥发性风味物质进行测定。结果 巴氏杀菌和高温杀菌能够较好的抑制微生物的繁殖,分别在贮藏第30 d和第60 d时菌落总数均低于国家标准。随着贮藏时间的延长,各组的TBA值都逐渐升高,感官评分逐渐降低。超高压杀菌在贮藏第15 d时超过国家限制标准,但对产品的质构和色差影响效小。不同杀菌方式均会对产品的风味产生一定的影响,但超高压杀菌对其影响最小。结论 超高压杀菌能够较好的保护产品的质构、色泽和风味,但货架期较短。巴氏杀菌和高温杀菌可以较好的延长产品的货架期,但对产品的质构、色泽和风味破坏较大。     

氧化锌纳米颗粒对玉米储藏过程中霉菌区系及其品质的影响

目的 探索氧化锌纳米颗粒对玉米储藏过程中霉菌区系及其品质的影响。方法 将玉米分成3份,经过不同浓度氧化锌纳米颗粒悬浮液的处理,以不添加氧化锌纳米颗粒作为对照,置于30℃下模拟储藏35 d,对不同处理组的玉米霉菌区系和储藏品质变化进行监测与分析。结果 储藏35 d后,处理组霉菌量为4.0×10⁴ CFU/mL,而对照组霉菌量为1.4×10⁶ CFU/mL,表明氧化锌纳米颗粒有效抑制了玉米储藏过程中霉菌的生长繁殖。玉米在整个储藏过程中优势霉菌主要为黄曲霉、黑曲霉、温特曲霉、桔青霉和查氏青霉等青霉属和曲霉属。随着储藏时间的增加,玉米中脂肪酸值、电导率、丙二醛显著上升,过氧化物酶活力显著下降,水分也呈下降趋势。揭示了低浓度氧化锌纳米颗粒对细胞膜有一定的保护作用,而高浓度氧化锌纳米颗粒会对细胞膜系统造成破坏。结论 氧化锌纳米颗粒可以显著抑制玉米储藏过程中霉菌的生长繁殖,同时低浓度添加更有利于玉米的储藏。     

Effect of salt,kinnow and pomegranate fruit by-product powders on color and oxidative stability of raw ground goat meat during refrigerated storage

Effects of salt, kinnow and pomegranate fruit by-product powders on color and oxidative stability of raw ground goat meat stored at 4 ± 1 °C was evaluated. Five treatments evaluated include: control (only meat), MS (meat + 2% salt), KRP (meat + 2% salt + 2% kinnow rind powder), PRP (meat + 2% salt + 2% pomegranate rind powder) and PSP (meat + 2% salt + 2% pomegranate seed powder). Addition of salt resulted in reduction of redness scores. Lightness increased in control and unchanged in others during storage. Redness scores declined and yellowness showed inconsistent changes during storage. Thiobarbituric acid reactive substances (TBARS) values were higher (P < 0.05) in MS followed by control and KRP samples compared to PRP and PSP samples throughout storage. The PSP treated samples showed lowest TBARS values than others. Percent reduction of TBARS values was highest in PSP (443%) followed by PRP (227%) and KRP (123%). Salt accelerated the TBARS formation and by-products of kinnow and pomegranate fruits counteracted this effect. The overall antioxidant effect was in the order of PSP > PRP > KRP > control > MS. Therefore, these powders have potential to be used as natural antioxidants to minimize the auto-oxidation and salt induced lipid oxidation in raw ground goat meat.     

包装方式对四角蛤蜊卤制风味产品贮藏品质的影响

目的：研究不同包装方式对其贮藏期品质的影响。方法 对四角蛤蜊卤制风味产品进行普通包装、真空包装、30% CO2+70% N2、50% CO2+50% N2、30% N2+70% CO2气调包装,并在4 ℃贮藏条件下,测定菌落总数、质构特性、色差、TVB-N值、风味特性等理化指标,选择最佳的包装方式。结果 普通包装样品在第3 d、真空包装组样品在第6 d时菌落总数超标,而气调包装组的货架期可达12 d左右。气调包装组的硬度、弹性、咀嚼性的下降程度都低于普通包装和真空包装组,气调包装的护色效果也优于其他两组。气调包装对TVB-N值、TBA值、pH值变化的延缓作用明显优于真空包装和普通包装。结论 不同包装方式对四角蛤蜊卤制风味产品贮藏品质的保持能力依次为气调包装、真空包装、普通包装,其中50% CO2+50% N2气调包装保鲜效果最佳,能显著延长产品货架期。     

不同涂膜保鲜剂对蒙自甜石榴冷藏品质的影响

目的探讨羧甲基纤维素钠(CMC)、海藻酸钠、魔芋和果胶4种涂膜保鲜剂对冷藏石榴品质的影响。方法以蒙自"甜绿籽"石榴为试验材料,涂膜处理后,在(5±1)℃低温冷藏,测定石榴籽粒中可溶性固形物、总糖、总酸、维生素C和腐烂率等指标随冷藏时间的变化。结果果胶涂膜处理能显著延缓贮藏期间可溶性固形物、总糖、总酸含量的下降,提高冷藏期间石榴的营养品质,效果优于其他涂膜保鲜剂;CMC涂膜处理能显著降低石榴的腐烂率,可延缓维生素C和可溶性固形物的损失;海藻酸钠涂膜处理可延缓可溶性固形物含量的降低,但是对维生素C、总糖、总酸和腐烂率无显著效果;魔芋涂膜处理能延缓总糖、总酸含量的下降,但是使腐烂率显著升高。结论果胶和CMC涂膜处理对冷藏石榴均有良好的保鲜效果。     

Development of a multispectral imaging system for online quality assessment of pomegranate fruit

The objective of this study was to develop a prototype multispectral imaging system for online quality assessment on pomegranate fruit. At first, a visible/near infrared spectroscopy (400–1100 nm) was tested for non-destructive determination of total soluble solids, titratable acidity, and pH. The spectral data were analyzed using the partial least square analysis. Then to establish consistent multispectral imaging system, the highest absolute values of β-coeffcients correspond to wavelengths from the best partial least square calibration model were selected and used for identifying the optimal wavelengths. Consequently, a multispectral imaging system was developed based on the effective wavelengths 700, 800, 900, and 1000 nm. The performance of the developed multispectral imaging system was evaluated by multiple linear regression models. The multiple linear regression model predict total soluble solids with r = 0.97, root mean square error of calibration = 0.21°Brix, and ratio performance deviation = 6.7 °Brix. Also, the results showed that the models had good predictive ability for pH and titratable acidity. Results showed that the developed multispectral imaging system based on the optimal wavelengths could be used for online quality assessment of pomegranate fruit.     

生姜精油-明胶涂膜对鸡肉贮藏期风味品质的影响

目的 为增加鸡肉在贮藏期的保鲜效果和保留鸡肉的品质。方法 本文设置未涂膜组、明胶涂膜组和精油-明胶涂膜组的鸡肉样品, 通过测定失重率、色泽、质构等指标评价鸡肉随着贮藏时间的变化; 结合扫描电镜、电子鼻和电子舌观察在相同贮藏条件下鸡肉肌肉组织结构、品质的变化。结果 实验表明, 在25 ℃环境下,随着贮藏时间的延长, 鸡肉的各种指标均发生明显变化, 组织结构亦受到不同程度地破坏, 表明鸡肉的品质逐渐下降。与未涂膜组相比, 精油-明胶涂膜组和明胶涂膜组鸡肉的失重率较低, 有较好的持水力; 色泽保护程度更好; 质地变化较为缓慢; 组织结构保持较完整, 且精油-明胶涂膜组的保鲜效果优于明胶涂膜组。电子鼻、电子舌的数据显示, 与明胶涂膜相比,加入生姜精油的复合明胶涂膜在气味和滋味上更接近新鲜鸡肉,表明精油-明胶涂膜更有利于保持鸡肉的气味和口感。结论 该文可得出明胶涂膜可延长鸡肉的保鲜效果期, 添加精油之后形成的精油-明胶涂膜更有利于保持鸡肉的品质, 为生鲜鸡肉的贮藏提供一种新方法。     

壳聚糖复合涂膜对冷藏虾蛄保鲜效果的影响

以虾蛄为研究对象,选用壳聚糖、维生素C、玉米淀粉为复合涂膜材料,以壳聚糖单一涂膜和空白作为对照,以感官、菌落总数(TVC)、pH值、挥发性盐基氮含量(TVB-N)、硫代巴比妥酸值(TBA)等为指标,研究复合涂膜对冷藏虾蛄品质的影响。结果表明:壳聚糖—维生素C—玉米淀粉复合涂膜有效延缓了虾蛄样品的菌落总数、pH值、TVB-N值、TBA值的上升,且效果优于空白组和壳聚糖单一涂膜组;与空白组相比,壳聚糖—维生素C—玉米淀粉复合涂膜可延长冷藏虾蛄货架期2～3d。     

超高压处理对冷藏鲈鱼品质的影响

研究了不同超高压条件(0、100、200、300 MPa,保压处理10 min)对鲈鱼冷藏过程中感官、p H值、白度、质构特性和持水性的影响。结果表明:鱼肉的感官评分、硬度、弹性和咀嚼度随贮藏时间的延长逐渐降低,白度逐渐升高,p H值先下降后上升,而持水性先上升后下降。超高压处理可显著提高鱼肉的硬度和咀嚼度(P0.01),同时提高了鱼肉的p H值和持水能力,增加了白度,200 MPa处理组的细菌总数低于对照组和其他2个处理组。此外,300 MPa的超高压处理对鲈鱼鱼肉品质的影响最大。综合感官和理化测定结果可知,超高压在改善鲈鱼肉质方面具有潜在的应用前景。     

微波焙烤咸干花生在贮藏过程中的品质与风味变化

选取生产上有代表性的鲁花、四粒红、大白沙3个花生品种,采用中试规模的隧道式微波炉进行干燥脱水,制备微波焙烤咸干花生产品,冷却后密封分装保存于室温（20℃）条件下,考察贮藏过程中产品主要理化指标酸价、过氧化值、水分含量和7种典型挥发性风味物质[2,5-二甲基吡嗪、2-乙基-3,5（6）-甲基吡嗪、2-乙基-6-甲基吡嗪、2-戊基呋喃、2,3-二氢苯并呋喃、苯甲醛、苯乙醛]含量的变化,采用Rancimat法推算产品货架期。发现随贮藏时间的延长,酸价、过氧化值增加,风味物质含量降低,其突变拐点均出现在27周左右,与产品货架期一致。进一步数据分析表明,酸价、过氧化值与水分含量呈显著的线性关系（p〈0.000 1）,其中酸价与水分含量的相关系数（R2值）为0.920 9,过氧化值与水分含量的R2值为0.963 9;典型相关性分析表明,风味成分含量与油脂氧化之间的相关关系显著,其中过氧化值与风味成分含量的关联度最大,R2值为0.993 0。原料不同,贮藏过程中微波焙烤花生品质和风味的变化也表现出一定差异,大白沙花生的酸价、过氧化值优于鲁花、四粒红,良好风味物质的总含量更高、损失速度更低,不良风味物质的含量更低、损失速度更高,与鲁花、四粒红相比,大白沙更适宜于生产微波焙烤咸干花生产品。     

不同气调包装对醉虾贮藏品质的影响

研究了40%CO2+60%N2和100%CO2的气调包装以及真空和空气包装4种包装方式对贮藏醉虾菌落总数、理化指标和感官指标的影响。结果表明:相对于真空和空气包装组,100%CO2或40%CO2+60%N2的气体包装,对醉虾的保鲜效果较好,其样品的菌落总数和挥发性盐基氮含量较低,质地和色泽变化较小,感官评分较高。但由于100%CO2包装随着贮藏时间的延长,气体收缩较明显导致产品包装外观不理想,40%CO2+60%N2的混合气体包装更适合于醉虾的贮藏。     

Effects of light-emitting diode illumination on the quality of fresh-cut cherry tomatoes during refrigerated storage

The effects of light-emitting diode (LED) illumination on the quality of fresh-cut cherry tomatoes were investigated. Tomatoes were exposed continuously to red, green, blue and white LED light for 7 days and control samples stored in darkness. Results showed that blue light treatment significantly led to more total soluble solids, lycopene concentration and individual phenolic compounds (chlorogenic acid, caffeic acid, rutin) after 7 days of storage. On day-5, green and blue light-treated tomatoes showed relatively higher firmness than samples treated by other lights and the control. At the early stage of storage, blue light could preserve the fresh flavour of tomatoes compared to other treatments. Overall, the blue light was most effective in the quality preservation of fresh-cut cherry tomatoes and could be used as a novel strategy in the preservation of fresh-cut fruits and vegetables during shelf life.     

Degradation of quality attributes of sweetened Julie and Ogbomoso mango juices during storage

Changes in the quality attributes of sweetened Julie and Ogbomoso mango juices were investigated. Sweetened mango juices were processed, bottled and stored at 25 °C for 12 weeks. The titratable acidity, pH, total solids, ash, soluble solids and ascorbic acid contents were evaluated immediately after processing and subsequently at 2-week intervals. The L*, a* and b* (HunterLab) parameters were determined to evaluate colour changes due to non-enzymatic browning.Generally, the quality attributes of the sweetened mango juices decreased during storage. The titratable acidity, pH, total solids, ash, soluble solids and ascorbic acid contents decreased during storage. After 12 weeks of storage, the percentage ascorbic acid loss of sweetened Julie and Ogbomoso mango juices was 16.25 and 16.67%, respectively. Browning index, chroma and b* values increased during storage. Colour changes in sweetened mango juices were mainly due to b* value and chroma.     

真空预冷对白蘑菇贮藏品质的影响

研究了真空预冷处理对白蘑菇贮藏品质的影响。结果表明,与不预冷样品相比,真空预冷抑制了白蘑菇呼吸强度,延缓了可溶性固形物、VC含量、细胞膜透性和质构的下降,改善了白蘑菇的感官品质,并延长了白蘑菇的货架期。     

Inhibition of lipid oxidation in anchovy oil (Engraulis encrasicholus) enriched emulsions during refrigerated storage

The aim of this study was to produce a functional emulsion product enriched with anchovy (Engraulis encrasicholus) oil. Tomato and garlic extracts were added to perform oxidative stability. Tomato and garlic extracts were added to avoid oxidative degradation in such a product. The plant extracts delayed the formation of primary and secondary oxidation products. The value of conjugated diens (3.07 ± 0.15) was markedly low in the emulsions containing garlic extract at the end of the storage period. The p–Av values of the emulsions treated with the extracts were significantly (P < 0.01) lower than untreated samples. TBARS formation increased slightly, therewithal statistical difference was not observed in the samples treated with garlic extract during the storage. Strong odour and flavour of the garlic suppressed the odour of fish oil. The panellists preferred the flavour, odour and aroma characteristics of the samples treated with the extracts.     

Quality changes in pomegranates during ripening and cold storage

The changes in the quality parameters of Spanish pomegranate fruit (cultivar Mollar) during ripening and during 7 weeks of cold storage at 5°C and 90–95% relative humidity were studied. The fruit and seed weights, as well as the surface colour increased with ripening. Total soluble solids (TSS), pH and titratable acidity (TA) did not show significant differences during the weeks studied (from the 26th to 32nd weeks after flowering), but the seeds' colour (Lab values) and juice colour (absorbance at 510 nm) showed an increase during this period with a maximum during the last 2 weeks. These results indicate that pomegranates should be harvested during the 31st to the 32nd after flowering, in order to get the best pigmentation without a decrease in other quality parameters. The anthocyanin profile changed during the different maturity stages, since the diglucoside derivatives were the prevailing pigments during the early ripening stages, whereas the monoglucoside derivatives were the main pigments in the latter stages. After cold storage of pomegranates harvested at two maturity stages, no differences in TSS, pH, TA and skin colour were observed. In addition, seeds' and juice colour did not decrease during storage. Hence, this study supports the theory that pomegranate is a nonclimacteric fruit and that pomegranates can be stored for at least 45 days without deterioration in the fruit quality.     

巴氏消毒乳储存过程中化学与微生物变化

通过研究不同储存温度的巴氏消毒乳感官品质、生化指标和微生物数量,来确定影响巴氏消毒乳品质的主要因素。结果表明,在5 d的储存期内,巴氏消毒乳在4℃和8℃储存条件下感官品质变化趋势几乎一样,在12℃储存条件下感官品质下降趋势较4℃和8℃储存条件下快。巴氏消毒乳中脂肪酶的活力、TBARS值和蛋白水解程度均随着储存时间的延长而逐渐升高,SDS-PAGE显示主要蛋白未见明显分解,金黄色葡萄球菌未检出,嗜冷菌的数量逐渐减少,菌落总数呈现对数生长趋势并在储存的第4天达到稳定期。巴氏消毒乳中残存的脂肪酶、蛋白酶和微生物是影响巴氏消毒乳品质的主要因素。