新鲜鱿鱼超高压杀菌工艺试验

为确定新鲜鱿鱼超高压杀菌工艺的最佳工艺参数,以杀菌压力、保压时间、漂烫温度为条件,设计了新鲜鱿鱼超高压杀菌试验。试验结果表明,90℃漂烫10 min,在400 MPa压力下保压10 min,此为新鲜鱿鱼超高压杀菌的最佳工艺条件。     

超高压杀菌技术对鲜驼乳品质的影响

本文利用超高压技术,以处理压力、保压时间和样品温度为变量,以微生物、理化性质及感官特性为检测指标,进行单因素和正交试验,就超高压处理对鲜驼乳品质的影响进行探讨,优化出超高压杀菌鲜驼乳的最佳工艺参数。结果表明,不同压力的超高压处理对鲜驼乳具有显著的杀菌作用,且随着处理压力和时间的增加其杀菌效果得到提升,其中600 MPa的超高压处理杀菌效果最佳;当时间超过20 min后,微生物的致死率无明显变化;当样品温度为40℃时致死率最低,超高压杀菌处理的结果最差。超高压处理后表观粘度增加,感官特性得到改善。通过正交试验得出,超高压处理鲜驼乳的最优条件为处理压力600 MPa、保压时间20 min、样品温度55℃。     

鱼肉肠的超高压杀菌工艺优化

研究鱼肉肠杀菌工艺处理压力、保压时间以及协同温度对微生物存活量的影响,并采用正交试验优化鱼肉肠的杀菌工艺条件。结果表明,在各因素中,处理压力是最重要的影响因素,温度次之,最后是保压时间。通过数据分析得出杀菌的最优工艺条件为处理压力400MPa、保压时间5min、协同温度30℃,在此条件下处理,鱼肉肠的菌落总数减少了97.25%,大肠菌群、霉菌和酵母菌致死率可达100%,致病菌在超高压处理前后均未检出。     

高静压对桃汁的杀菌效果及动力学模型

为了描述及预测高静压对桃汁的杀菌效果,研究了压力300,400,500,600MPa条件下保压3,5,10,15,20,25min的高压处理对桃汁中菌落总数、霉菌、酵母数的影响,并对不同压力条件下的杀菌效果进行动力学分析。研究结果表明,压力越高,保压时间越长,杀菌效果越好。霉菌、酵母对压力较为敏感,500 MPa以上的压力即可将其完全杀灭。Weibull模型在压力300～600 MPa时具有很好的拟合性(相关系数R~2>0.9)。尺度参数b随压力增大而增大,形状参数n则随压力的增大而减小。     

超高压处理泡菜的品质及杀菌效果研究

以甘蓝为原料加工泡菜。在单因素试验的基础上,选取超高压的压力、保压时间、食盐含量3个变量,进行BoxBehnken响应面设计,从而对泡菜的感官品质及杀菌效果进行优化。结果表明超高压处理泡菜的最佳工艺参数为压力350 MPa、保压时间15 min、食盐含量3.5%,泡菜的综合评分达到5.993。在保证泡菜品质的前提下,可有效杀死微生物,且大肠菌群检测均为阴性。     

腌制生食泥螺的超高压杀菌工艺研究

腌制生食泥螺为研究对象,利用正交试验设计方法研究了不同压力、保压时间和温度对腌制生食泥螺杀茵效果的影响.结果表明,超高压工艺对腌制生食泥螺杀菌效果显著(P相似文献   

西番莲果汁饮料超高压灭菌工艺优化

研究超高压对西番莲果汁饮料的杀菌工艺,采用先低压再高压处理的方式研究不同压力组合、保压时间、低高压保压时间比例、装载量、协同温度对西番莲果汁饮料菌落总数、色泽、可溶性固形物、pH等指标的影响。结果表明,超高压处理西番莲果汁饮料的最佳杀菌工艺参数为:压力组合为200～550 MPa,保压时间15 min,装载量100 g,低高压时间比例为2︰3,协同温度为42.5℃。在此工艺条件下,西番莲果汁饮料中的微生物几乎被全部杀灭,与巴氏杀菌相比,超高压具有较好的杀菌效果且对西番莲果汁饮料的品质影响小。该杀菌工艺的研究为西番莲果汁饮料的开发应用提供了理论基础。     

超高压对冷藏带鱼段的保鲜效果

研究了超高压预处理对4℃冷藏带鱼段保鲜效果的影响。试验以4℃冷藏带鱼段做对照,设置不同压力和保压时间(220 MPa、290 MPa,3、6、9 min)对带鱼进行超高压预处理后4℃贮藏,共7个试验组,每隔1天测定感官评定、菌落总数(TPC)、持水力(WHC)、挥发性盐基氮(TVB-N)、三甲胺氮(TMA-N)和硫代巴比妥酸(TBA)等指标。结果表明:超高压能有效抑制菌落的增殖,压力越高,保压时间越长,抑制作用越明显。冷藏组带鱼的货架期为4 d,220 MPa组的货架期延长至10 d,290 MPa组的货架期延长至12 d。随着压力的增大、保压时间的延长,超高压处理后鱼肉的透明度减少,持水力有所降低,但能有效抑制TMA-N的增长速度,并在一定程度上抑制带鱼的脂肪氧化。新鲜带鱼超高压处理后的TVB-N会随着压力的增大有所增加,在贮藏过程中,冷藏组的TVB-N的增长速度逐渐超过超高压组,且保压时间越长、压力越大,抑制TVB-N作用越好。其中290 MPa、6min超高压处理组,290 MPa、9 min超高压处理组保鲜效果最好,贮藏12 d时,带鱼的细菌总数分别为6.19、6.04 lg(CFU/g),TVB-N分别为19.87、20.86 mg N/100 g,基本都处在带鱼二级鲜度之内。     

生鲜毛蚶超高压杀菌工艺的研究

以生鲜毛蚶为研究对象,利用正交实验设计方法研究了不同压力、温度和保压时间对生鲜毛蚶中微生物(细菌、霉菌、酵母菌)存活率的影响,确定了生鲜毛蚶超高压杀菌工艺条件,为建立和推广海产品超高压杀菌工艺提供了实例。结果表明,当温度为20～40℃,保压时间为5～15min时,压力在300～500MPa范围内对生鲜毛蚶中各种微生物杀灭作用显著(P<0.01)。最终确定压力500MPa、温度40℃、保压时间5min为生鲜毛蚶超高压杀菌工艺。     

超高压和热处理对混合果蔬汁品质影响的比较研究

以混合果蔬汁为研究对象,对比研究热处理与超高压对混合果蔬汁品质的影响,以便为超高压技术在混合果蔬汁中的应用提供理论依据。结果表明:超高压处理能够很好的保持产品的品质,通过对不同压力和保压时间进行调节,对混合果蔬汁的杀菌效果、色泽、pH值、可滴定酸、可溶性固形物、抗坏血酸含量进行检测,得出超高压压力500 MPa,保压时间5 min时效果最好。     

高静压技术对豆浆中脂肪氧合酶的钝化效果及其动力学分析

研究了高静压技术(HHP)对豆浆中脂肪氧合酶(LOX)活性的钝化作用,并进行失活动力学分析。结果表明:HHP处理能显著钝化豆浆中LOX活性。用300～600MPa压力处理5～20min,对LOX活性有显著的钝化效果(P<0.05),并且随处理压力和处理时间的增加,酶的失活率提高。当压力500MPa,保压时间0min时也有一定的钝化LOX效果;当压力600MPa处理10min以上,豆浆LOX活性被完全抑制。用500MPa处理5min,可以达到与传统巴氏杀菌相同的钝酶效果(P>0.05)。HHP技术钝化豆浆LOX的过程可用一级动力学模型拟合(R2>0.900)。随着压力的升高和处理时间的延长,k值逐渐升高,D值逐渐减小;动力学参数ZP和Va分别为125.94MPa和-45.290cm3/mol。HHP技术在钝化豆浆中脂肪氧合酶活性方面比传统巴氏杀菌彻底,效果更好。其在改善豆浆品质方面具有良好的应用前景。     

超高压处理对发芽糙米酒中γ-氨基丁酸及挥发性成分的影响

以发芽糙米为原料酿造米酒,对发芽温度、发芽时间、超高压处理压力、超高压处理时间进行单因素实验,考察不同条件下酒中γ-氨基丁酸(γ-aminobutyric acid,GABA)含量,并对米酒成品采用顶空固相微萃取(HS-SPME)结合气相色谱质谱联用(GC/MS)技术检测发芽糙米酒中的挥发性成分。结果显示,发芽条件为温度28℃、时间20 h,获得的发芽糙米GABA含量较高,为346.7 μg/g。发酵后获得的发芽糙米酒GABA含量为24.7 mg/L。在超高压处理压力200 MPa、超高压处理时间30 min,获得的糙米酒成品GABA含量较高,达到27.4 mg/L。在200 MPa处理后的发芽糙米酒中共检测出醇类12种,酯类20种,酮类5种,酸类1种。相较于未经超高压处理的发芽糙米酒,超高压处理后的发芽糙米酒中酯类种类增加,醇类含量减少,酸类含量减少。通过感官评价,发现200和300 MPa处理的样品均优于未处理组,说明加压处理提高了发芽糙米酒的滋味,大大提高了米酒的风味品质。     

Efficacy of Pressure-Assisted Thermal Processing, in Combination with Organic Acids, against Bacillus amyloliquefaciens Spores Suspended in Deionized Water and Carrot Puree

ABSTRACT:  Effect of organic acids (acetic, citric, and lactic; 100 mM, pH 5) on spore inactivation by pressure-assisted thermal processing (PATP; 700 MPa and 105 °C), high pressure processing (HPP; 700 MPa, 35 °C), and thermal processing (TP; 105 °C, 0.1 MPa) was investigated.  Bacillus amyloliquefaciens  spores were inoculated into sterile organic acid solutions to obtain a final concentration of approximately 1.3 × 10⁸ CFU/mL.  B. amyloliquefaciens  spores were inactivated to undetectable levels with or without organic acids after 3 min PATP holding time. At a shorter PATP treatment time (approximately 2 min), the inactivation was greater when spores were suspended in citric and acetic acids than in lactic acid or deionized water. Presence of organic acids during PATP resulted in 33% to 80% germination in the population of spores that survived the treatment. In contrast to PATP, neither HPP nor TP, for up to 5 min holding time with or without addition of organic acids, was sporicidal. In a separate set of experiments, carrot puree was tested, as a low-acid food matrix, to study spore recovery during extended storage following PATP. Results showed that organic acids were effective in inhibiting spore recovery in treated carrot puree during extended storage (up to 28 d) at 32 °C. In conclusion, addition of some organic acids provided significant lethality enhancement ( P  < 0.05) during PATP treatments and suppressed spore recovery in the treated carrot puree.     

超高压处理对豆浆凝胶特性的影响

豆浆在２００～５００ＭＰａ超高压处理后,葡萄糖酸内酯点浆后加热时开始出现凝结的时间变迟,所形成的豆腐持水性升高、质地细腻,形成豆腐后的豆清中氮的含量降低,豆腐的得率提高。超高压的作用使得豆浆中蛋白质发生解聚和伸展,暴露了内部的－ＳＨ基团并促进二硫键的形成或交换,有利于豆浆形成豆腐。压力所导致的凝胶效果随压力的增大而增加,当压力≥３００ＭＰａ时即可使点浆后的豆浆形成质地细腻,持水性良好的豆腐凝胶。２００ＭＰａ超高压处理对豆腐的影响不大,但４００ＭＰａ超高压处理后,豆腐略有收缩并析水,豆腐的持水性下降、硬度略有增加。     

超高压对双孢蘑菇的杀菌效果和动力学的研究

以细菌总数、大肠菌群、酵母菌和霉菌数为对象,研究了超高压(High hydrostatic pressure,HHP)处理对双孢蘑菇(Agaricus bisporus)的杀菌效果和杀菌动力学。双孢蘑菇在300、400、500、600MPa压力下,室温下分别用HHP处理2.5～25min。结果表明:随压力的升高和时间的延长,杀菌效果增强;霉菌、酵母对压力较为敏感,400MPa处理2.5min可将其全部杀死;300MPa处理2.5min可完全杀灭双孢蘑菇中的大肠菌群。应用Weibull模型对不同处理条件下双孢蘑菇的杀菌效果进行拟合,拟合动力学曲线的决定系数R2均大于0.97,拟合效果较好。提出了双孢蘑菇的HHP杀菌的最优杀菌工艺参数,即600MPa处理5min,该条件即可以有效杀灭双孢蘑菇中的微生物。     

Inactivation of Bacillus cereus spores in milk by mild pressure and heat treatments

The objective of this work was to study the germination and subsequent inactivation of Bacillus cereus spores in milk by mild hydrostatic pressure treatment. In an introductory experiment with strain LMG6910 treated at 40 degrees C for 30 min at 0, 100, 300 and 600 MPa, germination levels were 1.5 to 3 logs higher in milk than in 100 mM potassium phosphate buffer (pH 6.7). The effects of pressure and germination-inducing components present in the milk on spore germination were synergistic. More detailed experiments were conducted in milk at a range of pressures between 100 and 600 MPa at temperatures between 30 and 60 degrees C to identify treatments that allow a 6 log inactivation of B. cereus spores. The mildest treatment resulting in a 6 log germination was 30 min at 200 MPa/40 degrees C. Lower treatment pressures or temperatures resulted in considerably less germination, and higher pressures and temperatures further increased germination, but a small fraction of spores always remained ungerminated. Further, not all germinated spores were inactivated by the pressure treatment, even under the most severe conditions (600 MPa/60 degrees C). Two possible approaches to achieve a 6 log spore inactivation were identified, and validated in three additional B. cereus strains. The first is a single step treatment at 500 MPa/60 degrees C for 30 min, the second is a two-step treatment consisting of pressure treatment for 30 min at 200 MPa/45 degrees C to induce spore germination, followed by mild heat treatment at 60 degrees C for 10 min to kill the germinated spores. Reduction of the pressurization time to 15 min still allows a 5 log inactivation. These results illustrate the potential of high-pressure treatment to inactivate bacterial spores in minimally processed foods.     

Effect of small, acid-soluble proteins on spore resistance and germination under a combination of pressure and heat treatment

To find the range of pressure required for effective high-pressure inactivation of bacterial spores and to investigate the role of alpha/beta-type small, acid-soluble proteins (SASP) in spores under pressure treatment, mild heat was combined with pressure (room temperature to 65 degrees C and 100 to 500 MPa) and applied to wild-type and SASP-alpha-/beta- Bacillus subtilis spores. On the one hand, more than 4 log units of wild-type spores were reduced after pressurization at 100 to 500 MPa and 65 degrees C. On the other hand, the number of surviving mutant spores decreased by 2 log units at 100 MPa and by more than 5 log units at 500 MPa. At 500 MPa and 65 degrees C, both wild-type and mutant spore survivor counts were reduced by 5 log units. Interestingly, pressures of 100, 200, and 300 MPa at 65 degrees C inactivated wild-type SASP-alpha+/beta+ spores more than mutant SASP-alpha-/beta- spores, and this was attributed to less pressure-induced germination in SASP-alpha-/beta- spores than in wild-type SASP-alpha+/beta+ spores. However, there was no difference in the pressure resistance between SASP-alpha+/beta+ and SASP-alpha-/beta- spores at 100 MPa and ambient temperature (approximately 22 degrees C) for 30 min. A combination of high pressure and high temperature is very effective for inducing spore germination, and then inactivation of the germinated spore occurs because of the heat treatment. This study showed that alpha/beta-type SASP play a role in spore inactivation by increasing spore germination under 100 to 300 MPa at high temperature.     

Model for Listeria monocytogenes inactivation on dry-cured ham by high hydrostatic pressure processing

The aim of the work was to develop and validate a model of the inactivation of Listeria monocytogenes on dry-cured ham by high hydrostatic pressure (HHP) processing, as a function of the technological parameters: intensity, length and fluid temperature. Dry-cured ham inoculated with L. monocytogenes was treated at different HHP conditions (at 347-852 MPa; for 2.3 to 15.75 min; at 7.6 to 24.4 °C) following a central composite design. Bacterial inactivation was assessed in terms of logarithmic reductions of L. monocytogenes counts on selective media. According to the best fitting and most significant polynomial equation, pressure and time were the most important factors determining the inactivation extent. The significance of the quadratic term of pressure and time indicated that little effect was observed below 450 MPa, whereas holding time longer than 10 min did not result in a meaningful reduction of L. monocytogenes counts. Temperature did not show significant influence at the range assayed. The model was validated with results obtained from further experiments and bibliographical data within the range of the experimental domain. The accuracy factor and bias factor were within the proposed acceptable values indicating the suitability of the model for predictive purposes, such as prediction of the process criteria to meet the Food Safety Objectives. The results of this work may help food processors to select optimum processing conditions of HHP.     

超高压在涮肉调料中抑菌处理的应用

对于半固体膏状调味品,常规热力抑菌措施很难有效保障产品的安全。但是超高压杀菌技术实现了常温或较低温度下杀菌和灭酶,保证了食品的营养成分和感官特性。本实验尝试以涮肉调料为样本,探讨非热力抑菌技术在半固体膏状调味品生产的应用。采用Box-Behnken响应曲面法分析压力、温度、保压时间等三因素的交互影响,得出影响的主次顺序为:压力>温度>保压时间,压力330MPa,保压时间16min,温度37℃的条为最佳参数。其结果为菌落总数为18000cfu/g,大肠菌群数<3.0(MPN/100g)。本次试验大肠杆菌均未检测出超标情况,大肠菌群阴性,MPN/g<3.0。     

热协同超高压对不同介质中嗜热脂肪芽孢杆菌芽孢的灭活作用

以磷酸缓冲液及经过人工接种的牛乳、鸡腿菇和卤牛肉为对象,考察超高压协同热处理对嗜热脂肪芽孢杆菌灭活的影响,测定处理前后的细菌菌落总数。结果表明,嗜热脂肪芽孢杆菌的失活率依次为:牛乳>磷酸缓冲液>鸡腿菇>卤牛肉。处理组500/60℃、500/90℃、600/80℃,5min、10min,牛乳中失活率(-2.18,-2.82,-3.32)高于磷酸缓冲液中的失活率(-1.62,-2.78,-2.98);卤牛肉中的失活率低于鸡腿菇中的失活率。说明在热协同超高压杀灭嗜热脂肪芽孢杆菌过程中,牛乳中存在利于诱导芽孢发芽的物质,使芽孢失去原有的对热的抵抗力,而在鸡腿菇和卤牛肉中失活率较牛乳低是由于其水分活度较低,卤牛肉中的失活率低于鸡腿菇中的失活率是由于NaCl对芽孢有保护作用,增加了其对压力的耐受性。