果蔬产品超高压加工的研究进展

采用超高压技术能在较低温度下达到一定的杀菌、灭酶作用,避免高温处理对食品营养物质造成的损失,受到越来越多的研究人员的关注。基于对大量外文资料的综合分析,本文综述了超高压对果蔬产品中微生物、内源酶、产品质地、感官品质、营养等方面影响的研究进展,分析超高压在果蔬产品加工中的应用前景。     

果蔬罐头高压杀菌研究

通过对不同压力，时间等参数及包装材料的选择，探讨果蔬罐头高压杀菌替代热力杀菌的可能性，研究结果表明，用６００ＭＰａ杀菌的绿豆芽和糖水梨罐头可达到商业无菌，能长期贮存，感官指标明显优于热力杀菌罐头。     

超高压和高温短时杀菌对绿色复合果蔬汁的杀菌效果与品质影响

通过感官评价,综合基本理化指标得出了一种较优的绿色复合果蔬汁的配方,并对比超高压(high hydrostatic pressure,HHP)和高温短时杀菌(high temperature short time,HTST)处理前后及其在4 ℃贮藏过程中的杀菌效果和理化品质变化。结果表明:对复合果蔬汁分别进行HHP(600 MPa/5 min)处理和HTST杀菌(86 ℃/15 s)处理后,果蔬汁中菌落总数从5.18 lg CFU/mL,下降至1.07 lg CFU/mL和1.11 lg CFU/mL,霉菌酵母、乳杆菌和嗜冷菌均未检出,达到国家要求的果蔬汁卫生标准;HHP处理后的果蔬汁总酚含量为43.645 μg/mL,显著高于HTST绿色复合果蔬汁;与HTST处理相比,HHP处理可以更好地保持复合果蔬汁的悬浮稳定性、色泽和抗氧化性等营养和品质指标。在4 ℃,15 d的贮藏期间,经HHP处理和HTST杀菌后的复合果蔬汁微生物指标均未超出国家卫生标准,且经HHP处理后的复合果蔬汁的悬浮稳定性、色泽品质、总酚含量和抗氧化能力等各项品质指标均优于HTST杀菌组。因此,HHP绿色复合果蔬汁保持了更好的品质。     

超高压对果蔬制品品质影响研究进展

超高压技术是一项非热加工技术,它在食品工业的发展中得到了越来越广泛的应用。从超高压对果蔬汁、鲜切果蔬块的杀菌效果、酶、营养成分及感官品质的影响角度系统介绍和分析超高压对果蔬制品品质影响的研究现状,初步探讨超高压在处理过程中的机理,并分析今后这一领域研究的趋势。     

高压处理过程中的压力和能量分析

利用高压均质过程作为比较,本文分析了超高压处理过程中流体的压力和能量转化,从而找出了超高压处理过程中没有引起较高温升现象的原因,为进一步理解超高压杀菌技术提供一定的理论基础。     

超高压对果蔬汁品质影响研究进展

超高压技术是一种新型的非热力加工技术。文中从果蔬汁的颜色品质、香气品质、营养品质及流变特性和稳定性等角度系统介绍和分析了超高压对果蔬汁品质影响的研究现状,并分析了今后这一领域研究的趋势。     

超高压对草莓果肉饮料的杀菌效果与品质影响

研究不同超高压条件(压力600MPa,保压时间分别为0、2、4、6、8、10min)对草莓果肉饮料的杀菌效果及600MPa、4min超高压处理前后草莓果肉饮料理化品质的变化。结果表明：在600MPa、4min的超高压条件下,草莓果肉饮料中的细菌、霉菌和酵母可全部被杀死,并且该处理前后草莓果肉饮料中的可溶性固形物、pH值、可滴定酸、颜色、总酚含量及抗氧化性均无显著性差异(P＞0.05),但VC含量损失9.2%、花青素含量损失20.6%;超高压处理后草莓果肉饮料中部分酯类成分损失,醇类物质种类及数量增加(P＜0.05),但仍保持草莓原有的特征风味。     

高静压技术对豆浆品质的影响

本文研究发现,400MPa以上的高静压能有效地灭活豆浆中的微生物,当压力为400—600MPa、保压时间为0—20min时,豆浆中的菌落总数、霉菌和酵母数分别降低0.51-3.69、0.31-2.83个对数级。其中经600MPa、20min处理,豆浆中的菌落总数不能检出。HHP处理后豆浆的色泽无明显变化(ΔE<2);pH略有升高(P<0.05);表观粘度增加,其流变特性指数n有所减小,粘稠系数K有所增大,但是HHP处理对K和n值的影响均小于巴氏杀菌处理的豆浆,HHP处理较巴氏杀菌能更好地保证食品的品质。     

Combined Carbon Dioxide and High Pressure Inactivation of Pectin Methylesterase, Polyphenol Oxidase, Lactobacillus plantarum and Escherichia coli

ABSTRACT: High pressure processing (HPP) and CO₂have both been shown to increase food product shelf-life. CO₂ was added at approximately 0.2 molar % to solutions processed at 500 to 800 MPa in order to further inactivate pectin methylesterase (PME), polyphenol oxidase (PPO), L. plantarum ATCC 8014, and E. coli K12. An interaction was found between CO₂ and pressure at 25 °C and 50 °C for PME and PPO, respectively. Activity of PPO was decreased by CO₂ at all pressure treatments. The interaction between CO₂ and pressure was significant for L. plantarum with a significant decrease in survivors due to the addition of CO₂ at all pressures studied. No significant effect on E. coli survivors was seen with CO₂ addition.     

High Hydrostatic Pressure Effects on Vegetable Structure

Cryo-fracture scanning electron microscopy revealed the changes that cauliflower and spinach leaves undergo after treatment with high hydrostatic pressure. High pressure changed cell permeability and enabled movement of water and metabolites from inside to outside of the cell. The ultrastructure showed that parenchyma organization disappeared in spinach leaf and cavity formation occurred after treatment. However, cauliflower exhibited a firm structure with a soaked appearance and would be more suitable than spinach for high hydrostatic pressure treatment.     

Factors Affecting Bacterial Inactivation during High Hydrostatic Pressure Processing of Foods: A Review

Although, the High Hydrostatic Pressure (HHP) technology has been gaining gradual popularity in food industry since last two decades, intensive research is needed to explore the missing information. Bacterial inactivation in food by using HHP applications can be enhanced by getting deeper insights of the process. Some of these aspects have been already studied in detail (like pressure, time, and temperature, etc.), while some others still need to be investigated in more details (like pH, rates of compression, and decompression, etc.). Selection of process parameters is mainly dependent on type of matrix and target bacteria. This intensive review provides comprehensive information about the variety of aspects that can determine the bacterial inactivation potential of HHP process indicating the fields of future research on this subject including pH shifts of the pressure treated samples and critical limits of compression and decompression rates to accelerate the process efficacy.     

超声加工技术对果蔬汁品质影响及其作用机制研究进展

传统热加工虽然能有效灭酶和灭菌,但会对果蔬汁的色泽、营养物质及风味等品质造成严重破坏。超声技术作为一种新型的非热加工技术,能够改善果蔬汁的稳定性、安全性、感官特性和营养特性,已广泛用于果蔬汁加工的研究中;但由于受到复杂因素的影响,超声波处理也可能对果蔬汁产生不利影响。本文综述了国内外有关超声技术应用于果蔬汁加工的最新研究进展,从果蔬汁内源酶、微生物（发酵微生物、致腐和致病微生物）、理化特性和营养成分（如抗坏血酸、多酚和类胡萝卜素）等不同视角深入分析了超声波处理对它们的影响及作用机制,并总结了现阶段超声技术所存在的问题及研究趋势,为超声技术在果蔬汁加工中的应用提供一定的理论基础。     

Effects of High Hydrostatic Pressure Processing on Hen Egg Compounds and Egg Products

High hydrostatic pressure (HHP), used alone or with other processes, is an emerging technology increasingly used in the food industry to improve microbial safety, and the functionality and bioactive properties of food products. HHP provides a way to reduce energy requirements for food processing and may contribute to improved energy efficiency in the food industry. Hen egg is used by the food industry to formulate many food products. To improve the microbiological safety of egg and egg‐derived products, HHP processing is an attractive alternative to heat‐ pasteurization and a potential technology. However, HHP treatment induces structural modifications of egg components (such as proteins) which could positively or negatively affect the physicochemical and functional properties of egg‐derived products. Improving our knowledge regarding the potential of HHP in the egg industry will add value to the final food products and increase profitability for egg producers and the food industry.     

超高压处理对鲜杏鲍菇品质的影响

本文以新鲜杏鲍菇为研究对象,研究了超高压不同处理方式下(不同压力100 MPa、150 MPa、200 MPa、250 MPa、300MPa,不同保压时间3 min、6 min、9 min、12 min、15 min、18 min),对杏鲍菇多酚氧化酶(PPO)、失重率、色差、硬度、感官等品质的影响。研究结果表明,超高压处理后杏鲍菇的PPO酶活力和弹性随着压力的升高和保压时间的延长出现先下降后上升的变化,色差的亮度(L*)值和硬度则逐渐降低,黄度(b*)值和失重率则逐渐增加。在储藏期内(0~12 d),贮藏温度为4℃,超高压处理下(压力200 MPa保压时间9 min)的酶活力低于未处理的杏鲍菇样品,而高压处理的失重率增幅大于未处理组样品,而色差和硬度变化则小于未处理组样品。通过实验分析得到杏鲍菇超高压处理的最佳压力和保压时间参数为:200 MPa、9 min。     

Development and Characterization of Edible Films Based on Fruit and Vegetable Residues

Edible films were developed from the solid residue of the processing of whole fruits and vegetables. The solid residue, processed into flour (FVR flour) was chemically and structurally characterized by microstructure, elemental composition, structural links, and moisture sorption isotherm. Films were prepared by casting using aqueous extracts of 8% and 10% of flour (w/w) and characterized in terms of thickness, water solubility, mechanical properties, water vapor permeability, and Fourier transform infrared (FTIR). The analysis of microstructure and elemental composition, performed on flour (mean particle size 350 μm), showed an essentially granular aspect, with the presence of fibrous particles having potassium as one of the most abundant elements. FTIR results showed similarity between the characteristic bands of other raw materials used in edible films. The sorption isotherm of FVR flour showed a typical profile of foods rich in soluble components, such as sugars. Dried films presented an average thickness of 0.263 ± 0.003 mm, a homogenous aspect, bright yellow color, pronounced fruit flavor, and high water solubility. The FTIR spectra of the edible films revealed that addition of potato skin flour did not change the molecular conformation. Moreover, the films presented low tensile strength at break when compared with fruit starch‐based films.     

高静压加工对新鲜蛋液微生物及品质的影响

研究在不同处理压力和时间条件下,高静压对新鲜全蛋液微生物(细菌总数、大肠菌群)、色泽、乳化特性(乳化活力、乳化稳定指数)及起泡特性(起泡性、泡沫稳定性)的影响。结果表明:200 MPa处理10 min,全蛋液微生物指标已符合国家标准;相比空白组,400 MPa处理10 min,全蛋液乳化活力及乳化稳定性显著增加,300 MPa处理20 min及400 MPa处理10 min全蛋液起泡性较好,而400 MPa处理10~15 min及500 MPa处理5~15 min可使全蛋液颜色更鲜亮。综上,适当的高静压处理可使全蛋液达到有效杀菌且改善其品质的目的。     

高静水压对产β-胡萝卜素粘红酵母的诱变效应

利用100～500 MPa的静水高压和10～30 min的保压时间对粘红酵母（Rh. glutinis RG5）进行处理,发现处理10 min时的高压存活曲线呈现马鞍形,说明高静水压处理的最终效应可能是多种生物学效应的累积.150 MPa保压20 min时的突变株RG5-3的生物量虽然比出发菌株RG5下降了9.25%,但目的产物β-胡萝卜素的质量分数却比RG5提高了68.60%.传代实验表明,该诱变株遗传稳定性良好,没有发生性状退化及回复突变.利用限制性片段长度多态性分析（RFLP）比较发现,限制性内切酶HindⅢ和BamHⅠ切割的RG5和RG5-3的DNA片段有明显不同,证明高静水压使粘红酵母RG5在表面性状和DNA水平上都发生了改变.     

Does High Hydrostatic Pressure Affect Fruit Esters?

The effect of high hydrostatic pressure on ester formation and hydrolysis was studied. Six esters and the corresponding carboxylic acids and alcohols were subjected to high-pressure treatments of 400 and 800 MPa under three different pH conditions (namely, buffer solutions of pH 4, 6 and 8). The selected compounds were dissolved into buffer solutions, subjected to the pressure treatment and then extracted using dichloromethane. The analysis and quantification were carried out by gas chromatography with flame ionization as detector. High pressure appeared to have no effect on ester formation or hydrolysis under the investigated conditions. In all cases, a small decrease at the levels of carboxylic acids and esters was observed without any evidence of further reaction. This decrease, referred to as decomposition, depended on pressure and pH conditions. Ester decomposition was minimised when a high-pressure treatment of 400 MPa in basic conditions (pH 8) was applied. Carboxylic acid decomposition was minimal in basic conditions and it was independent of the pressure applied.     

外界因子对超高压杀灭枯草芽孢杆菌效果的影响

超高压是一种有效的灭菌消毒技术。本研究通过鉴别设计(scfeening design)法对影响超高压杀菌效果的外界因子，如：压力、温度、保压时间、升压速度、卸压速度进行了关键因子考察与评价，试验结果表明：温度、压力、保压时间对灭活枯草芽孢杆菌影响显著，升压速度和卸压速度对灭活枯草芽孢杆菌影响不显著。     

基因工程在果蔬生产加工中的应用

基因工程技术给果蔬加工业带来了新的革命,本文综述了基因工程在果蔬加工诸多方面的应用,并对基因工程在果蔬加工中的应用前景作了展望。