3种包装物对大包装番茄酱产品色差的影响研究

选取3种包装的36%~38%冷破番茄酱为研究对象,对比分析番茄酱产品出厂检验指标与存放1~2年后色差指标的变化。结果表明,220 L钢桶装和1 500 L铁箱装番茄酱产品在2年的保质期内,产品色差值下降分别为0.130和0.125;1 250 L木箱装番茄酱产品在2年的保质期内,产品色差值下降0.093。     

不同储藏温度下玻璃罐装番茄酱色泽变化的动力学研究

以新疆玻璃罐装番茄酱(24°Brix)为原料,以亮度L*值、红值a*、黄值b*、色差值△E、褐变指数和5-羟甲基糠醛(5-HMF)含量为考察指标,研究不同贮藏温度(10、25、35℃)对新疆玻璃罐装番茄酱色泽变化的影响,并在此基础上建立新疆玻璃罐装番茄酱色泽变化动力学模型,以预测玻璃罐装番茄酱褐变程度。结果表明:玻璃罐装番茄酱的色泽参数L*值、a*值、b*值变化符合一级动力学反应,色差值△E符合零级动力学反应,褐变指数和5-羟甲基糠醛含量变化在25℃和35℃下符合一级动力学反应。褐变指数、5-羟甲基糠醛含量、L*值、红值a*、黄值b*和色差值△E等各指标变化的活化能分别为74.30、65.22、45.46、55.72、102.26和64.21 kJ/mol。     

电子鼻 电子舌对不同规格番茄酱风味的分析

采用电子鼻和电子舌,通过主成分分析(Principal component analysis,PCA)、线性判别分析(Linear discriminant analysis,LDA)对不同规格番茄酱的风味品质进行检测区分,定量辨别不同规格番茄酱之间的风味差异。结果表明,不同规格番茄酱嗅觉、味觉指标丰富,热破番茄酱在短链烷烃类、醇醛醚酮等类和芳香成分、有机硫化物类物质成分上高于冷破番茄酱;味觉差异主要表现在酸味、苦味、咸味和鲜味指标上,冷破番茄酱酸味、咸味强于热破番茄酱,热破番茄酱苦味和鲜味均高于冷破番茄酱。     

冷热破碎工艺对小包装番茄酱贮藏期间非酶褐变的影响

为探究冷破碎工艺和热破碎工艺对番茄酱贮藏期间非酶褐变的影响,将制备的番茄酱在20℃和35℃条件下进行12个月的贮藏。通过对番茄酱的褐变指数、还原糖、番茄红素、5-HMF、VC含量、氨基酸态氮含量、可滴定酸含量和pH变化的测定以及相关性分析得出美拉德反应与VC氧化分解反应是导致番茄酱在贮藏期间发生非酶褐变的主要原因,番茄红素不是引起番茄酱色泽变化的主要原因,美拉德反应的主要产物是5-HMF。经过液相色谱分析,番茄酱中糖类主要由果糖、葡萄糖和蔗糖组成,冷破、热破番茄酱中的三种糖类含量有差异。通过模拟体系,进一步确定了美拉德反应是导致番茄酱在贮藏期间发生非酶褐变的根本原因,且糖是5-HMF生成的必要条件,5-HMF的产生主要由果糖决定,VC氧化分解反应对5-HMF的生成贡献微弱。因冷破碎工艺温度较低,产品果糖含量较多,更容易褐变,所以冷破番茄酱的贮藏环境应尽可能的保证低温。     

均质压力对豆乳贮存过程中物性变化的影响

以豆乳为原料,通过不同均质压力处理后,将样品存放在常温(25℃)环境下,持续观测30 d,研究不同均质压力下贮存过程中豆乳的黏度、色差、丙二醛含量和蛋白稳定性的变化。发现在15～40 MPa的均质压力下,豆乳黏度无明显差别;贮存过程中,色差△E值在第20天时为8.51,感官评价消费者中不可接受,黏度和稳定性有极大差异。     

酸、铝浸种对萝卜种子萌发和芽苗生长的影响

以萝卜为供试材料,研究了酸、铝浸种对萝卜种子萌发和芽苗生长的影响.结果表明,中强度的酸、铝浸种处理(pH≤4.5、铝浓度100～1 000μmol/L)对种子发芽率无显著影响,但显著提高了发芽势、发芽指数和活力指数,而对芽苗根长、茎长、芽苗总长、根重、地上部鲜重等生长指标有一定的抑制作用.低浓度铝(0～ 10μmol/L)处理时,芽苗生长指标随pH值(5.5～3.5)的下降,先上升后下降;中高浓度铝(100～5 000μmol/L)处理时,则随pH值的下降而不断下降;芽苗生长指标随铝浓度的增加总体呈下降趋势,且根系受胁迫影响最大,是反应最敏感的部位.这些结果表明,萝卜种子萌发期较芽苗生长期对酸、铝胁迫有更强的耐性.当pH值低于4.5,铝浓度达到1 000μmol/L时,即可显著抑制萝卜芽苗生长.     

热改性聚合乳清蛋白对酸豆奶发酵及贮藏稳定性的影响

研究改性聚合乳清蛋白(PWPC和PWPI)对酸豆奶发酵特性、凝乳状态及贮藏稳定性的影响。结果表明,加入聚合浓缩乳清蛋白PWPC溶液7%和0.02%硬脂酰乳酸钠SSL150,并选用5株乳酸菌混合酸奶发酵剂(保加利亚乳杆菌、嗜热链球菌、双歧杆菌、嗜酸乳杆菌和干酪乳杆菌),接种量为3%,发酵制得的产品状态稳定、黏度和硬度适中、口感细滑、组织柔软、风味良好。最终样品pH值为4.5~4.6,滴定酸度为65~700°T,干物质含量达到了12.36%,贮藏28 d产品稳定性良好。     

转基因作物深加工产品的DNA提取方法研究

由于转基因作物深加工产品中的DNA受到破坏,含量低、质量下降,提取困难,直接影响了后续的转基因定性检测。为解决这一难题,以酱油和番茄酱为样本进行了原料DNA提取方法的试验。针对酱油中添加大量焦糖色素和番茄酱偏酸的特点,通过加入样品预处理程序,有效地去除了酱油中的焦糖色素分子和调整了番茄酱沉淀的pH 值。利用大豆和番茄的内源特异参照基因进行PCR扩增,结果证明了利用该方法所提取的DNA完全能够满足转基因定性检测的需要,方法简单、快速、有效。     

干酪的凝乳及成熟条件对感官品质的影响

研究了干酪的最佳凝乳及成熟条件。结果表明,以63℃,30min杀菌乳为基础,添加3%的发酵剂,0.01%的CaCl2及40mg/kg的凝乳酶,在32～35℃下凝乳35～40min,干酪的产率可达13.2%。向凝乳粒中添加3%的食盐,然后压榨成型,在温度为8℃,相对湿度80%～85%的条件下,成熟50d,干酪的风味品质良好,pH值4.6,SN为7.29%。在干酪成熟前期(20d),乳酸菌数虽然显著下降,但仍具有较高的发酵产酸活性,pH值降至最低(5.95)。然后,随着蛋白质水解产物的积聚,pH值开始回升,30d后pH值基本稳定在6.10～6.15。随着成熟时间的延长,蛋白质水解程度(pH值4.6 SN和12%TCA SN)逐渐增大,从而引起干酪的色泽逐渐变黄,硬度降低,弹性下降。     

芋头淀粉性质的研究

比较不同浓度下芋头淀粉和其他种类淀粉的性质。结果表明,10%的淀粉乳产生的凝胶韧性很强,随着芋头淀粉浓度的增加,其透明度和析水率逐渐下降,黏度逐渐增加;食盐、蔗糖都有助于提高芋头淀粉的黏度,而析水率下降,食盐能降低其透明度,蔗糖有助于提高其透明度;pH值接近中性,其黏度较高,在较高和较低的pH值,其透明度和析水率都较高;淀粉的溶解度随着温度的升高而增大。     

The use of historical datasets to develop multi-trait selection models in processing tomato

Multi-trait indices (MTI) weigh traits based on their importance to facilitate selection in plant and animal improvement. In animal breeding, economic values are used to develop MTIs. For vegetables, economic data valuing traits are rarely available. We posit that varieties with traits valued by growers and processors achieve higher market share and longer life span. Our objective was to develop MTIs predicting success of tomato varieties. Historical data for the California processing tomato industry from 1992 to 2013 provided measurements for yield, soluble solids (Brix), color, pH, market share, and life span for 258 varieties. We used random models to estimate best linear unbiased predictors (BLUPs) for phenotypic traits of each variety, and evaluated trends over time. Yield has been increasing from 2006, while Brix stayed constant. Because yield and Brix are negatively correlated, this trend suggests that Brix influenced selection. The average number of resistances reported in varieties ranking in the top ten increased from 2 to 4.5 between 1992 and 2013. MTIs predicting success from phenotypic traits were developed with general linear models and tested using leave-one-out cross validation. MTIs weighing yield, Brix, pH and color were significantly correlated to success metrics and selected a significantly higher proportion of successful varieties relative to random sampling. The index multiplying yield and brix, suggested in the literature, was not significantly correlated with variety success. The MTIs suggested that fruit quality had less of an influence on variety success than yield. The MTIs developed could help improve gain under selection for quality traits in addition to yield.     

果胶酶处理对5个品种橙汁主要理化指标的影响

将5个主要汁用品种的橙(哈姆林、特罗维他、锦橙、橘橙、凤梨甜橙),去皮打浆后加入相同质量分数的(0.1%)果胶酶(PectinexBeXXL,NovoEnzyme),经45℃水浴、酶解1h后,与未酶解样品相比较,分析果胶酶对不同品种橙汁主要理化指标的影响。结果表明,经果胶酶处理的各品种橙汁的Brix、果汁澄清度、钙含量及可溶性果胶的含量增加,而pH值、可滴定酸和黏度均降低。但此酶处理对各橙汁的色泽及游离氨基酸含量的影响,不同品种间存在一定的差异。其中凤梨甜橙与特罗维他橙汁的酶解样品与未酶解样品的色泽差异显著(△E>2),凤梨甜橙主要体现在a*(红值)增加,而特罗维他则主要体现在b*(黄值)的降低,其余样品则差异不显著;哈姆林、锦橙和橘橙的酶解样品的游离氨基酸总量较低,主要体现在天冬氨酸、丝氨酸、谷氨酸和组氨酸含量较低,特罗维他的酶解样品与非酶解样品差异不显著,而凤梨甜橙的酶解样品除苏氨酸外,其余均显著增加。这些数据将为橙汁加工中酶的选择以及橙汁的鉴伪提供参考,     

毛酸浆果酒的发酵工艺研究

以新鲜毛酸浆为原料,采用液态发酵法,研究酵母接种量、初始糖度、初始pH值和发酵温度对毛酸浆酒理化指标和感官评价的影响,采用正交试验方法优化并得到最佳发酵工艺条件,最终获得具有毛酸浆独特风味的毛酸浆果酒。结果表明,毛酸浆酒最佳发酵工艺条件为:发酵温度28℃,酵母接种量0.1%,初始pH值3.5,初始糖度18 Brix。     

响应面法优化陇南黄樱桃低糖保健酱配方研究

以陇南黄樱桃鲜果为原料,添加黄果槲寄生果实多糖等材料进行加工,研制低糖复合果酱.通过单因素试验,对黄樱桃果肉含量、木糖醇和柠檬酸添加量及黄果槲寄生果实多糖添加量进行筛选.根据感官评分,采用Box-Benhnken中心组合设计试验,优化陇南黄樱桃低糖保健酱的配方.结果表明,低糖陇南黄樱桃保健酱的配方为:黄樱桃果肉61.28％,木糖醇16.19％,柠檬酸0.18％,黄果槲寄生果实多糖0.33％,氯化钙0.02％,D-异抗坏血酸钠0.10％,由该配方制得的陇南黄樱桃低糖保健酱色鲜黄,有光泽,甜酸适口,组织状态良好,可溶性固形物含量55.54％,总糖含量34.36％,pH 3.86,黏度25.89 cm/30 s.     

Sensory interpretation of instrumental measurements 2: sweet and acid taste of apple fruit

The relationship between objective and sensory measurements of apple taste and flavour was investigated. The aim was to determine the objective parameters that were best correlated with sensory evaluation, and then to identify the minimum objective difference that was required before a trained sensory panellist could detect a difference in apple taste and/or flavour. Objective measures included titratable acidity, °Brix (soluble solids content), levels of individual volatiles, sugars and acids, as well as calculations of °Brix/titratable acid ratio. Sensory panellists were trained to assess sweet taste, acid taste, apple flavour, and overall flavour. Titratable acidity was the best predictor of acid taste (correlation of 0.86 for the median panellist), and differences between apples of 800 mg kg⁻¹ (0.08% titratable acid) were required before the average trained panellist could detect a difference in acid taste (P=0.90). This value represented about a tenth of the range of titratable acidity values of the treatments presented to the trained panel. Sweet taste was difficult to predict using any of the objective methods. Indeed, the best objective predictor of sweetness was °Brix (correlation of 0.41 for the median panellist), which could predict a difference in taste when apples differed by more than 1 °Brix (P=0.90). This value represented about a third of the range of °Brix levels presented to the trained panel. Thus, while acid taste may be predicted on the basis of titratable acidity, we recommend that evaluation of sweet taste and flavour attributes continue to require assessment by trained sensory panels.     

慢照射与茎尖培养相结合筛选甘薯同质突变体

甘薯品种玉丰、高系14号和Kandaba在生育期内用60Coγ射线慢照射, 对照射后的材料进行茎尖组培, 通过体细胞胚胎发生途径再生出大量植株. 将这些再生植株移栽到大田, 对辐照后代的形态特征和经济特性进行了调查和分析. 结果表明, 辐照后代M1V 1和M1V2在顶叶形、叶形、顶叶色、叶脉色、脉基色、薯形及薯肉色、产量、干物率、食     

以鱿鱼内脏为原料酿制鱿鱼酱油的工艺研究

以鱿鱼内脏为原料加食盐酿制鱿鱼酱油,以氨基态氮、可溶性氮和挥发性盐基氮为指标,并结合感官评定方法,研究发酵温度、pH值、加盐量等对酿制效果的影响。最终确定酿制条件如下:料液比1∶1,食盐质量分数15%,温度45℃,发酵pH值7,发酵30 d。在上述条件下酿制原料利用率高,产品色泽风味好,可溶性盐基氮、氨基态氮含量高,挥发性盐基氮含量低。