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超高压加工对鲜榨胡萝卜汁品质的影响 总被引:1,自引:0,他引:1
重点研究了热敏性胡萝卜汁经200~600MPa超高压处理10min后其感官品质、理化性质及营养品质的变化情况。实验结果表明:经高压处理后胡萝卜汁色泽、可溶性固形物、总糖、α-和β-胡萝卜素含量与对照样相比差异不明显(P>0.05);总抗氧化能力在400MPa压力处理后降低较显著,600MPa处理有较显著的提高(P<0.05);此外,超高压处理后胡萝卜汁的pH降低,总酸含量增加,且样品的沉降稳定性提高,且变化都比较显著(P<0.05)。综合实验各方面的处理效果,600MPa处理后的胡萝卜汁品质最佳。因此,超高压能较好保持胡萝卜汁原有的品质和营养价值,可达到保持营养、提高品质和延长货架期的目的。 相似文献
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研究了高压二氧化碳(HPCD)对梨汁中多酚氧化酶(PPO)酶活钝化效果、透明度、色泽和褐变度的影响,并分析贮藏期酶活、透明度和色泽稳定性。结果表明,经HPCD(30MPa-40℃-60min)处理后梨汁中PPO残存酶活为19%;其钝酶效果显著高于相同温度的热处理(p<0.05),说明HPCD钝酶过程中温度和CO2形成的压力具有协同灭酶作用;且在4℃条件下贮藏8周也能较好抑制PPO酶活。HPCD处理能抑制贮藏期梨汁透光率降低和梨汁酶促褐变、保持鲜榨梨汁的色泽,对保持鲜榨梨汁品质贮藏稳定性有较好效果。90℃-10min热处理也能有效钝化PPO酶活,但是在高温加热过程中促进非酶褐变,并且使梨汁透光率下降,增大梨汁浊度,对梨汁品质保持不利。 相似文献
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研究了超高压(HHP,500 MPa/4 min)和高温短时(HTST,95℃/15 s)对甘蔗浊汁和清汁p H、可滴定酸(TA)、可溶性固形物(TSS)、总酚、色泽、褐变度、澄清度、浊度和微生物指标的影响,并分析了4℃,贮藏15 d内甘蔗汁品质的变化。结果表明:HTST和HHP处理对甘蔗汁均具有较好的杀菌效果,HHP和HTST甘蔗清汁p H显著降低,HTST甘蔗清汁可滴定酸(TA)含量升高,HHP和HTST对甘蔗清汁和浊汁的可溶性固形物(TSS)和总酚含量无影响,与HTST相比HHP对甘蔗汁颜色的影响较小,HHP处理后甘蔗清汁澄清度升高,甘蔗浊汁浊度下降,HHP甘蔗汁感官性能优于HTST甘蔗汁。经在4℃贮藏15 d,甘蔗浊汁的菌落总数显著升高,但浊汁和清汁的霉菌和酵母菌数基本保持稳定,贮藏期间甘蔗清汁和HTST甘蔗浊汁p H降低,总酚含量均有明显升高,甘蔗清汁的澄清度和甘蔗浊汁的浊度有所降低,HHP甘蔗清汁的b*值和褐变度增加,HTST甘蔗汁颜色稳定。结论:超高压杀菌有利于保持甘蔗汁品质,是适合甘蔗汁的加工技术。 相似文献
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目的评定高效液相色谱法测定橙汁中果糖含量的不确定度。方法采用高效液相色谱法测定橙汁饮料中果糖的含量,建立数学模型,对检测过程中可能引入不确定度的因素包括样品的处理、标准溶液配制、标准曲线拟合及样品的重复测定进行分析及评定,最终合成橙汁中果糖含量测定结果的不确定度。结果橙汁中果糖含量测定结果是33.5 g/kg时,在95%的置信区间下,扩展不确定度为1.88 g/kg (k=2)。结论不确定度的主要来源是标准溶液配制和标准曲线拟合。 相似文献
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Bing Hu Malik Muhammad Hashim Muhammad Saeeduddin Shicheng Lei Tao Wu Xiaoxiong Zeng 《International Journal of Food Science & Technology》2014,49(11):2449-2457
The combined effects of ultrasound (US) and high hydrostatic pressure (HHP) on enzymes, micro‐organisms, colouring pigments, total polyphenols, ascorbic acid and physicochemical properties of carrot juice were investigated. Carrot juice was treated with sonication (20 kHz, 70% amplitude) and HHP (250, 350, 450 MPa) at room temperature for 10 min. For comparison, fresh carrots were water blanched (WB) at 100 °C for 4 min and carrot juice was then extracted. As results, highest improvements in colouring pigments were observed in WB and US‐HHP450 treatments, which also completely inactivated micro‐organisms. The highest reduction in enzymes was observed in WB treatment followed by US‐HHP450. Total polyphenol contents increased significantly in US, HHP and US‐HHP treatments with the highest increase in US‐HHP450, but it decreased significantly in WB treatment. Ascorbic acid contents significantly decreased in WB and HHP450, while increased in US and US‐HHP treatments. Results indicate that US‐HHP450 treatment improves the quality of carrot juice and serves as a good alternative for blanching treatment. 相似文献
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Felix N Engmann Yongkun Ma Haining Zhang Lizhi Yu Nana Deng 《Journal of the science of food and agriculture》2014,94(11):2345-2356
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The paper aims at investigating the potential application of non-thermal innovative technologies, such as high hydrostatic pressure, for the sanitization of functional liquid foodstuffs. A 100% pomegranate juice was selected for the experiments, due to its high bioactive compounds content. The operating pressure, temperature and holding times at the pressure set point were changed over a wide range, with the aim of optimizing the processing condition in order to assure the microbiological stability of the processed juice as well as preserve the natural content of the functional compounds. The experiments clearly demonstrate that the high pressure treatment at room temperature improves the quality of pomegranate juice, increasing the intensity of red color of the fresh juice and preserving the content of natural anthocyanins. The residual activity of some enzymes at the end of high pressure processing, independently on the processing conditions, such as the polyphenoloxidase (PPO), causes the degradation of the nutraceutical compounds as observed in particular processing conditions, thus suggesting that the optimal combination of the processing parameters should take into account the degradation of the anthocyanins as well as the enzymatic activity. 相似文献
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超高压处理对鲜榨桃汁多酚氧化酶(PPO)活力影响的研究 总被引:1,自引:0,他引:1
桃汁中的PPO是耐高压的酶,200~500MPa的压力处理使果汁中PPO活力逐渐降低,但降低幅度不大,400MPa的压力对PPO有激活作用。高于600MPa的压力,失活PPO的效果开始显著。VC在500MPa以下对果汁中PPO有激活作用,在600MPa以上或热处理结合高压时有钝化PPO的作用。随着保压时间的延长和温度的升高,桃汁中多酚氧化酶相对活性逐渐降低。500MPa60℃或750MPa50℃以上的处理强度可使鲜榨桃汁中的PPO失去61%以上的活力。 相似文献
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Comparative study on shelf life of orange juice processed by high intensity pulsed electric fields or heat treatment 总被引:1,自引:0,他引:1
Pedro Elez-Martínez Robert C. Soliva-Fortuny Olga Martín-Belloso 《European Food Research and Technology》2006,222(3-4):321-329
The effects of high intensity pulsed electric fields (HIPEF) processing (35 kV/cm for 1,000 μs; bipolar 4-μs pulses at 200 Hz)
on the microbial shelf life and quality-related parameters of orange juice were investigated during storage at 4 and 22 °C
and compared to traditional heat pasteurization (90 °C for 1 min) and an unprocessed juice. HIPEF treatment ensured the microbiological
stability of orange juice stored for 56 days under refrigeration but spoilage by naturally occurring microorganisms was detected
within 30 days of storage at 22 °C. Pectin methyl esterase (PME) of HIPEF-treated orange juice was inactivated by 81.6% whereas
heat pasteurization achieved a 100% inactivation. Peroxidase (POD) was destroyed more efficiently with HIPEF processing (100%)
than with the thermal treatment (96%). HIPEF-treated orange juice retained better color than heat-pasteurized juice throughout
storage but no differences (p<0.05) were found between treatments in pH, acidity and °Brix. Vitamin C retention was outstandingly higher in orange juice
processed by HIPEF fitting recommended daily intake standards throughout 56 days storage at 4 °C, whereas heat-processed juice
exhibited a poor vitamin C retention beyond 14 days storage (25.2–42.8%). The antioxidant capacity of both treated and untreated
orange juice decreased slightly during storage. Heat treatments resulted in lower free-radical scavenging values but no differences
(p<0.05) were found between HIPEF-processed and unprocessed orange juice. 相似文献
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The objective of this study was to assess the effect of High Pressure Homogenisation (HPH) compared with High Hydrostatic Pressure (HHP) on the microbiological quality of raw apple juice during storage at ideal (4 °C) and abuse (12 °C) temperatures. In the case of HPH, only low numbers of micro-organisms were detected after treatment at 300 MPa (typically between 2 and 3 log.ml−1). These were identified as Streptomyces spp., and numbers did not increase during storage of the juice for 35 days, irrespective of storage temperature. In the case of HHP, the total aerobic counts were also reduced significantly (p < 0.05) after treatment for 1 min at 500 and 600 MPa and the numbers did not increase significantly during storage at 4 °C. However, during storage at 12 °C the counts did increase significantly (p < 0.05) and by day 14 counts at 500 MPa were not significantly different from the control juice. This confirms that good temperature control is important if the full benefits of HHP treatment are to be realised.Frateuria aurantia dominated the microbiota of the HHP apple juice stored at 12 °C along with low levels of Bacillus and Streptomyces spp.The HPH and HHP juices both turned brown during storage indicating that neither treatment was sufficient to inactivate polyphenol oxidase. The enzyme is known to be pressure resistant and this discolouration was controlled by a heat treatment (70 °C for 1 min) used in commercial practice and given prior to HP treatment. 相似文献
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Hidenobu Sumitani Sachiko Suekane Aya Nakatani Kiyoaki Tatsuka 《Journal of the science of food and agriculture》1997,75(1):73-79
White peach (Prunus persica L cv Yamane) homogenates with sugar (20%), or with sugar (20%) and/or L -ascorbic acid (0·1%) and/or sodium chloride (0·5%), were packed in plastic bottles, pressurised (400 MPa, 20°C, 10 min), and then stored at 0 and 25°C for various periods. The headspace volatiles which were absorbed on Tenax TA using dynamic headspace sampling were heat desorbed and analysed by capillary gas chromatography mass spectrometry. Enzymatic formation of benzaldehyde during storage was observed in all samples. The homogenate with L -ascorbic acid showed the highest level of benzaldehyde formation. The flavour quality and colour of the pressurised homogenates with ascorbic acid stored at lower temperature were excellent. © 1997 SCI. 相似文献
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José V. Carbonell José L. NavarroLuís Izquierdo Enrique Sentandreu 《Journal of food engineering》2013
Lane Late orange juice with extended shelf life (3 months at 3 °C) was obtained by high pressure homogenization (HPH) at 150 MPa at 68 °C for 15 s. Residual pectinmethylesterase (PME) inactivation level achieved was 75% but its cloudiness was maintained during storage and its acceptability undistinguishable from that of fresh juice during the assayed period. Juices with entire and reduced (50% and 25%) pulp contents were also homogenized at 150 MPa at different temperatures (63 °C and 58 °C for 15 s) to establish an appropriate shelf life of orange juices according to a desired level of cloudiness. Results showed how cloud stability of pulp reduced samples, even with a residual PME inactivation level above 90%, was not satisfactory (as in the case of entire juices homogenized out of 68 °C). The proposed methodology can easily be implanted by citrus industry to obtain high quality chilled orange juices with prolonged shelf life. 相似文献
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Del Pozo-Insfran D Del Follo-Martinez A Talcott ST Brenes CH 《Journal of food science》2007,72(4):S247-S253
ABSTRACT: Intermolecular copigmentation is one of the mechanisms of stabilization of anthocyanins in nature and is also responsible for the characteristic color and stability of aged red wines. In the present study, the effect of polyphenol oxidase (PPO) activity on phytochemical stability of an ascorbic acid-fortified muscadine grape juice following high hydrostatic pressure (HHP) processing (400 and 550 MPa for 15 min) and after 21 d of storage at 25 °C was investigated. Addition of rosemary and thyme polyphenolic extracts (copigmentation) was evaluated as a means to stabilize anthocyanins and ascorbic acid during pressurization and subsequent storage. Polyphenolic extracts were partially purified in order to reduce their content of PPO substrates, and improve their stabilization properties within juice matrix. Overall PPO activity increased (3- and 2.5-fold) following HHP at 400 and 550 MPa, respectively, although it was significantly lower in copigmented treatments. Higher anthocyanin losses occurred at 400 (∼70%) than at 550 MPa (∼46%), which were correlated to antioxidant losses ( r = 0.89). Similarly, greater ascorbic acid losses were observed at 400 (84%) than at 550 MPa (18%). Copigmentation increased anthocyanin retention in reference to pressurized controls (3- and 3.2-fold for rosemary and thyme treatments, respectively) and decreased ascorbic degradation (20 to 32%). In stored samples, higher anthocyanin content (>2-fold) and antioxidant capacity (>1.5-fold) was observed for copigmented treatments when compared to control juices. Addition of partially purified copigments increased muscadine grape juice color, antioxidant activity and also reduced phytochemical losses during HHP processing and storage. 相似文献
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The effect of high hydrostatic pressure on the microbiological quality and safety of carrot juice during refrigerated storage 总被引:1,自引:0,他引:1
The microbial quality of untreated and pressure-treated carrot juice was compared during storage at 4, 8 and 12 °C. High pressure treatment at 500 MPa and 600 MPa (1 min/20 °C) reduced the total counts by approximately 4 log CFU ml−1 and there was very little growth of the survivors during storage at 4 °C for up to 22 days. Total counts increased during storage of pressure-treated juice at 8 °C and 12 °C but took significantly longer to reach maximum levels compared to the untreated juice. The microflora in the untreated juice consisted predominantly of Gram-negative bacteria, identified as mostly Pantoea spp., Erwinia spp. and Pseudomonas spp. Initially the pressure-treated juice contained low numbers of spore-forming bacteria (Bacillus spp. and Paenibacillus spp.) and Gram-positive cocci; the spore-formers continued to dominate during storage. 相似文献
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Guanghe Zhao Ruifen Zhang Mingwei Zhang 《International Journal of Food Science & Technology》2017,52(1):3-12
Fresh fruits and vegetables have been reported to possess a variety of bioactivities partly due to their high abundance of phenolics. However, traditional thermal pasteurisation during fruit and vegetable processing typically induces a pronounced loss of phenolic compounds. In contrast, nonthermal pasteurisation techniques, especially high hydrostatic pressure (HHP) processing, are beneficial to the retention of phenolics. In addition to more effectively keeping original freshness, flavour and colour of fruit and vegetable products to the greatest extent, in most cases, HHP processing and subsequent storage more effectively sustain the levels of phenolic compounds and antioxidant activity in fruit and vegetable products compared with thermal pasteurisation. Therefore, HHP processing has a huge potential to preserve fruit and vegetable products rich in phenolic compounds. 相似文献