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81.
Lijuan Xie Yibin Ying Hongjian Lin Ying Zhou Xiaoying Niu 《Sensing and Instrumentation for Food Quality and Safety》2008,2(2):111-115
The potential of near-infrared (NIR) transmittance spectroscopy to nondestructively detect soluble solids content (SSC) and
pH in tomato juices was investigated. A total of 200 tomato juice samples were used for NIR spectroscopy analysis at 800–2400 nm
using an FT-NIR spectrometer. Multiplicative signal correction (MSC), and the first and second derivative were applied for
pre-processing spectral data. The relationship between SSC, pH, and FT-NIR spectra of tomato juice were analyzed via partial
least-squares (PLS) regression. PLS regression models were able to predict SSC and pH in tomato juices. The r
c, RMSEC, RMSEP, and RMSECV for SSC were 0.92, 0.0703°Brix, 0.150°Brix, and 0.138°Brix, respectively, whereas those values
for pH were 0.90, 0.0333, 0.0316, and 0.0489, respectively. It is concluded that the combination of NIR transmittance spectroscopy
and PLS methods can be used to provide a technique of convenient, versatile, and rapid analysis for SSC and pH in tomato juices. 相似文献
82.
83.
为从新疆主栽杏品种中选择出适宜加工的优良品种,对杏原浆品质及稳定性进行探讨,选用了库车小白杏等10个新疆地区种植面积较大的主要栽培品种作为试材,分别在杏浆加工完成当天及室温贮存至第5、10、15、20、25、30、35天取样测定了总糖度、总酸度、Vc含量和褐化度(用波长420nm时OD值表示)等与加工性状相关的指标。参试品种35d内所测数据显示:糖含量呈缓慢下降趋势,平均损失率为12.41%;酸含量呈缓慢增加趋势,平均增加了9.35%;Vc含量呈明显下降趋势,平均损失率是80.76%,且下降趋势随时间的推移逐渐放缓;OD值呈缓慢上升的趋势,OD值平均增加了6.73%。通过聚类分析可将参试杏品种分成3类,其中第2类(大果胡安娜、阿哥亚格勒克、脆佳娜丽)平均糖含量最低为8.40%,平均含酸量最高0.912%,Vc平均含量最高0.427mg/100g,OD平均值最小0.319,是最适宜的杏浆加工品种。 相似文献
84.
85.
本文就几种常用的果汁澄清方法在无花果果汁上的应用进行了研究比较。结果表明,果胶酶—明胶—硅溶胶澄清法是无花果果汁澄清的较好方法,用此法生产澄清无花果果汁稳定可靠、易于操作,制得的果汁澄清度高并且可保持原有风味。 相似文献
86.
87.
Inactivation of Penicillum expansum in sour cherry juice, peach and apricot nectars by pulsed electric fields 总被引:1,自引:0,他引:1
Inhibitory effects of pulsed electric fields (PEF) on Penicillum expansum inoculated into sour cherry juice, apricot and peach nectars were determined based on germination tube elongation, spore germination rate, and light and scanning electron microscopy (SEM) observations in this study. After inoculation of juice/nectar samples with P. expansum spores at the level of 10(5)-10(6)cfu/mL, the samples were processed by bench scale PEF pulse generator as a function of differing electric field strengths (0, 13, 17, 20, 23, 27, 30 and 34kV/cm) and processing times (0, 62, 94, 123, 163, 198 and 218mus). Results revealed that with an increase in electric field strength and processing time, germination tube elongation and spore germination rate were completely inhibited. Light and SEM observations revealed considerable morphological alterations in fungal conidia such as cytoplasmic coagulation, vacuolations, shrinkage and protoplast leakage. PEF processing of juice/nectars was demonstrated to be effective in inactivating P. expansum. To our knowledge, this is the first study confirming the inhibitory effects of PEF on germination tube elongation and spore germination rate of P. expansum in fruit juice/nectars. 相似文献
88.
研究了胡萝卜汁添加对乳化肠色泽、质构特性、保水性以及感官品质的影响。基于最优基础配方,实验通过控制胡萝卜汁的添加量(0%、5%、10%、15%),探索其对于乳化肠食用品质的影响。结果表明:添加胡萝卜汁组与对照组(胡萝卜汁添加量0%)的色差、质构以及感官方面存在显著差异(P0.05)。随着胡萝卜汁添加量的增加,红度值、硬度都呈显著下降趋势,而蒸煮损失、黏聚性和弹性与对照组没有显著差异。胡萝卜汁添加量为10%的样品组的硬度、咀嚼性和胶着性最好,且通过感官评定得知该组各项指标综合评定结果最好,本实验得出10%是胡萝卜汁较优的添加量。 相似文献
89.
预处理对增加红富士苹果细胞壁物质降解和出汁率的影响 总被引:1,自引:1,他引:1
为了通过简便易行的预处理增强果实细胞壁物质降解,提高苹果果实出汁率。文中测定了500mg/L乙烯利(E_1)和100mg/L乙烯利配合60℃热水(E_2)处理,对红富士果实堆放期细胞壁酶活性、细胞壁物质含量和出汁率的影响。结果表明:E_1使其果胶甲酯酶(PME)、纤维素酶(CS)活性高峰分别比对照提前6、3d,多聚半乳糖醛酸酶(PG)活性在前15d持续高于对照,木聚糖酶(Xyl)活性基本不变;处理12d后,果实细胞壁多糖中果胶类多糖、半纤维素类多糖和细胞壁残渣多糖含量分别下降到对照的80.1%、70.4%和75.7%;处理后9~18d,红富士苹果的出汁率较对照提高2.3%~4.0%;E_2抑制了果实PME活性,却普遍增强了0~6d内PG、Xyl、CS活性,亦促进了各类细胞壁物质的降解,0~9d内果实出汁率较对照高3.2%~7.1%。 相似文献
90.
Yiwei Mo Deqiang Gong Guobin Liang Ruihong Han Jianghui Xie Weicai Li 《Journal of the science of food and agriculture》2008,88(15):2693-2699
BACKGROUND: Salicylic acid (SA) is recognised as an endogenous signal, mediating in plant defense and against pathogens. It has been reported that SA treatment can reduce decay and extend storage life of various fruit, such as bananas, peaches and apples. RESULTS: Physiological and biochemical responses in harvested sugar apple fruit (Annona squamosa L.) to SA at 0.4, 0.8 and 1.2 mmol L?1 were investigated during post‐harvest storage. Results indicated that SA treatments lowered respiration, increased activities of antioxidant enzymes of superoxide dismutase (SOD), peroxidase (POD), catalase (CAT) and ascorbate peroxidase (APX), decreased lipoxygenase (LOX) activity and correspondingly lowered Malondialdehyde (MDA) contents in treated fruits was observed as compared to the control. Moreover, production of superoxide free radical (O2?, ?) and ethylene was significantly decreased in the treated fruits. Total soluble solids, total soluble sugar, softness and decay rate were significantly lowered in treated fruits, and in turn a delay in the fruits ripening process was achieved after 10 days of storage. CONCLUSION: SA has positive effects in maintaining membrane integrity and in delaying fruit ripening process, which results in improved storability of sugar apple. Copyright © 2008 Society of Chemical Industry 相似文献