Microbial quality

微生物质量
  • 文章类型: Journal Article
    在市售蜂蜜中,应用热处理来防止变质可能会损害其有益的性能和质量,这些影响随着存储的延长而恶化。正在探索蜂蜜的高压处理(HPP),但其对蜂蜜质量的长期影响尚未明确。本研究评估了HPP和热加工对微生物负荷的影响,物理化学质量(即,羟甲基糠醛含量和淀粉酶活性),处理后和在20°C下延长储存(6、12和24个月)后的蜂蜜的抗氧化能力。巴氏杀菌(78°C/6分钟)有效消除了蜂蜜中的微生物,但损害了其物理化学质量和抗氧化活性。HPP最初显示亚致死性失活,但是与未加工的蜂蜜和在温和条件下(55°C/15分钟)热处理的蜂蜜相比,储存加速了蜂蜜中酵母/霉菌和需氧中温细菌的减少(储存24个月后<1logCFU/g)。经过HPP处理的蜂蜜和未加工的原始蜂蜜的质量的理化特性在长期储存(24个月)后确实发生了变化,但仍在法规标准之内。总之,HPP作为一种更适合、更安全的阿皮蜂蜜保鲜方法,与传统的工业蜂蜜巴氏杀菌相比,抗氧化活性损失的风险最小。
    In commercially available honey, the application of a heat treatment to prevent spoilage can potentially compromise its beneficial properties and quality, and these effects worsen with extended storage. The high-pressure processing (HPP) of honey is being explored, but its long-term impact on honey quality has not been characterised yet. This study evaluated the effects of HPP and thermal processing on the microbial load, physicochemical quality (i.e., hydroxymethylfurfural content and diastase activity), and antioxidant capacity of honey after treatment and following extended storage (6, 12, and 24 months) at 20 °C. Pasteurization (78 °C/6 min) effectively eliminated the microorganisms in honey but compromised its physicochemical quality and antioxidant activity. HPP initially showed sublethal inactivation, but storage accelerated the decrease in yeasts/moulds and aerobic mesophiles in honey (being <1 log CFU/g after 24 months of storage) compared to unprocessed honey and honey thermally treated under mild conditions (55 °C/15 min). The physicochemical characteristics of the quality of HPP-treated honey and raw unprocessed honey did change after long-term storage (24 months) but remained within regulatory standards. In conclusion, HPP emerged as a more suitable and safe preservation method for Apis mellifera honey, with a minimal risk of a loss of antioxidant activity compared to traditional industrial honey pasteurization.
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  • 文章类型: Journal Article
    在斯里兰卡,在三个地理海拔的不同农业气候区域的工厂中生产了几种茶叶等级。该研究旨在确定从不同地点的工厂获得的不同茶级和复合茶样品的微生物质量。平均APC,不同等级茶中的酵母和霉菌计数和大肠菌群范围为3.4×103至2.0×104cfu/g,4.8×102至2.5×103cfu/g和0.005至3.9×101最可能数(MPN)/g。从不同工厂收集的茶叶样品的APC和酵母和霉菌的平均值为5.3×103±1.3×103cfu/g和9.7×102±1.9×102cfu/g。大肠杆菌(E.大肠杆菌)和沙门氏菌在茶级或复合样品中均未检测到。茶叶样品中鉴定的微生物属于厚壁门,变形杆菌,子囊,担子菌和孢子菌。从中部国家海拔收集的样品的APC计数最高,而酵母和霉菌计数在低国家海拔地区很高。超过70%的测试样品符合红茶微生物学品质的SLTB指南。细菌的分布,相对于地理区域,茶的酵母,霉菌和大肠杆菌密度显着变化。
    In Sri Lanka, several tea grades are produced in factories located in different agro-climatic regions within three geographical elevations. The study aimed to determine the microbial quality of different tea grades and composite tea samples obtained from factories situated at diverse locations. The average APC, yeast & mould counts and coliforms in different tea grades ranged from 3.4 × 103 to 2.0 × 104 cfu/g, 4.8 × 102 to 2.5 × 103 cfu/g and 0.005 to 3.9 × 101 Most Probable Number (MPN)/g respectively. The tea samples collected from different factories had mean values of APC and yeast & mould as 5.3 × 103±1.3 × 103 cfu/g and 9.7 × 102±1.9 × 102 cfu/g. Escherichia coli (E.coli) and Salmonella were not detected either in tea grades or in composite samples. The identified microorganisms in tea samples belong to phyla Firmicutes, Proteobacteria, Ascomycota, Basidiomycota and Zygomycota. The samples collected from the mid country elevation had the highest counts of APC and yeast & mould counts were high in the low country elevation. More than 70 % of the tested samples comply with the SLTB guidelines given for the microbiological quality of black tea. The distribution of bacterial, yeast and mould and coliform densities of tea were significantly variable with respect to geographic areas.
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  • 文章类型: Journal Article
    本研究旨在评估采后向日葵和玉米秸秆残留物的乙醇提取物的抗氧化能力,以及它们对化学成分的影响,物理化学参数,脂质氧化稳定性,微生物特性,和90天储存期猪肝的感官特征。制备了四种制剂:对照组(CON)、用丁基化羟基甲苯作为合成抗氧化剂(BHT)的批次,1%乙醇提取物从向日葵残留物(SSRE),和1%乙醇提取物从玉米残留物(MSRE)。相对于SSRE,MSRE具有较高的总酚含量并且显示出更好的抗氧化活性(p<0.01)。添加SSRE降低了猪肝的亮度,增加了猪肝的发红,与对照相比,这些p表现出最高的总色差(p<0.01)。作物提取物增加了pés中的n-6和总PUFA含量,并改善了PUFA/SFA比(p<0.01)。含有作物残渣提取物的制剂显示出比对照组和BHT组更高的TBAR和POV值(p<0.01),表明在储存过程中的促氧化剂作用和加速的脂质氧化。就微生物质量而言,作物残渣提取物的存在减少了总的活菌数量,乳酸菌,和精神需氧菌(p<0.01)。在猪肉中掺入作物提取物会损害其感官质量,特别是颜色,气味,香气,和味道,并降低了他们的整体接受度。这些结果表明,虽然作物残渣提取物在保持脂肪稳定性方面不如合成抗氧化剂有效,他们证明了提高这种肉类产品微生物质量的潜力。
    The present study aimed to evaluate the antioxidant capacity of ethanolic extracts from post-harvest sunflower and maize stalk residues, and their impact on the chemical composition, physicochemical parameters, lipid oxidative stability, microbiological properties, and sensory characteristics of pork liver pâtés over a 90-day storage period. Four formulations were prepared: a control group (CON), a batch with butylated hydroxytoluene as a synthetic antioxidant (BHT), 1% ethanolic extract from sunflower residues (SSRE), and 1% ethanolic extract from maize residues (MSRE). The MSRE had a higher total phenol content and showed better antioxidant activity relative to the SSRE (p < 0.01). The addition of SSRE decreased the lightness and increased the redness in the pork liver pâtés, with these pâtés showing the highest total color difference compared to the control (p < 0.01). The crop extracts increased the n-6 and total PUFA contents in pâtés and improved the PUFA/SFA ratio (p < 0.01). Formulations containing crop residue extracts showed higher TBARs and POV values than the control and BHT group (p < 0.01), indicating a pro-oxidant effect and accelerated lipid oxidation in pâtés during storage. As far as microbiological quality, the presence of crop residue extracts decreased the total viable count, lactic acid bacteria, and psychotropic aerobic bacteria (p < 0.01). The incorporation of crop extracts in the pork pâtés impaired their sensory quality, particularly color, odor, aroma, and flavor, and decreased their overall acceptability. These results indicated that, while the crop residue extracts were not as effective as synthetic antioxidants in preserving the lipid stability of pâtés, they demonstrated potential for enhancing the microbial quality of this type of meat product.
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  • 文章类型: Journal Article
    在这项研究中,评估了在山羊肉丸中添加芒果种子提取物(MSE)。三种分歧水平的MSE提取物的功效,即T1=(2.5毫升/100克肉乳剂v/w),T2=(5.0毫升/100克肉糜v/w),T3=(7.5毫升/100克肉糜v/w),和T0(不含芒果籽提取物的对照),进行水活度(AW)变化的评估,pH值,总酚类化合物,DPPH,过氧化值,TBARS,微生物质量,和在冷藏温度(4±1°C)下储存的山羊肉丸的感官属性。掺入芒果种子提取物T3(7.5mL/100g)表明,它可以潜在地更好地保持pH和水活度的变化。在整个储存过程中,所有样品的总酚和DPPH活性显着下降(P0.05);然而,在所有样本中,T3的值最高.添加MSE的山羊肉丸(T3)组具有比其他样品更低的显著(p<0.05)的过氧化物值。与其他处理相比,添加有MSE的T3样品表现出显著(p<0.05)更低的TBRAS值。在整个储存时间期间,在处理组中维持了相对较低的微生物增殖和较好的感官属性。结果表明,包含MSE提取物T3(7.5mL/100g)是一种有前途的天然抗氧化剂,可在好氧包装条件下在冷藏温度(4±1°C)下保持山羊肉丸的较好质量。
    In this study, the addition of mango seed extract (MSE) in goat meatballs was assessed. The efficacy of three different levels of MSE extract, namely T1 = (2.5 mL/100 g of meat emulsion v/w), T2 = (5.0 mL/100 g of meat emulsion v/w), T3 = (7.5 mL/100 g of meat emulsion v/w), and T0 (control without mango seed extract), was conducted for evaluation of changes in water activity (aW), pH, total phenolic compounds, DPPH, peroxide value, TBARS, microbial quality, and sensory attributes of the goat meatballs stored at refrigerated temperature (4 ± 1 °C). Incorporation of the mango seed extract T3 (7.5 mL/100 g) showed that it can potentially better maintain change in pH and water activity. Total phenolic and DPPH activity decreased significantly (P0.05) among all samples throughout storage; however, the highest value was noted for T3 among all samples. The MSE-added goat meatballs (T3) group had lower significant (p < 0.05) peroxide values than the other samples. The T3 sample added with MSE exhibited significant (p < 0.05) lower TBRAS values as compared to other treatments. Comparatively lower microbial proliferation and better sensory attributes were maintained among the treated groups during the entire storage time. The results show that the inclusion of MSE extract T3 (7.5 mL/100 g) is a promising natural antioxidant that can maintain a better quality of goat meatballs at refrigerated temperature (4 ± 1 °C) under aerobic packaging conditions.
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  • 文章类型: Journal Article
    黄油是一种易腐烂的食物,它的微生物变质发生在制冷条件下,导致保质期缩短和感官性能丧失。本研究旨在研究奇亚籽提取物(CSE)对2°C巴氏杀菌甜奶油黄油的微生物和感官特性的影响。制备奇亚籽的乙醇提取物,并以0.05%的浓度添加到黄油样品中,0.1%,0.25%,和0.5%(v/w),在60天冷藏期间,每隔15天评估其对微生物和感官质量的影响。结果表明,在黄油处理中添加0.25%和0.5%CSE可将总活菌计数降低0.25-0.6logCFU/g,总嗜冷计数为1-1.5logCFU/g,在储存的第45天和第60天,与对照样品相比,大肠杆菌计数为3-4logCFU/g。此外,与对照样品相比,在第30-60天,浓度为0.1%-0.5%CSE的霉菌和酵母计数减少了1.5-2.6logCFU/g。在储存过程中,任何样品中均未检测到大肠杆菌和金黄色葡萄球菌。CSE在60天储存期间对黄油样品的感官特性(除了香气)具有显著影响。最好的颜色,风味,与对照样品相比,包含0.1%-0.5%CSE的处理被分配和总体接受度评分。可以得出结论,在冷藏和巴氏杀菌的黄油中添加0.1%和0.25%CSE可以延缓微生物腐败并同时改善其感官性能。
    Butter is a perishable food, and its microbial deterioration occurs in refrigeration conditions, leading to a reduction in shelf life and a loss of sensory properties. This study aimed to investigate the effect of chia seed extract (CSE) on the microbial and sensory properties of pasteurized sweet cream butter at 2°C. Ethanolic extract of chia seeds was prepared and added to the butter samples in concentrations of 0.05%, 0.1%, 0.25%, and 0.5% (v/w), and its effects on microbiological and sensory quality were evaluated at 15-day intervals during 60-day refrigerated storage. The results indicated that the addition of 0.25% and 0.5% CSE to butter treatments decreased total viable counts by 0.25-0.6 log CFU/g, total psychrotrophic counts by 1-1.5 log CFU/g, and coliform counts by 3-4 log CFU/g compared to the control sample on days 45 and 60 of storage. Moreover, concentrations of 0.1%-0.5% CSE reduced mold and yeast counts by 1.5-2.6 log CFU/g on days 30-60 of storage compared to the control sample. Escherichia coli and Staphylococcus aureus were not detected in any samples during storage. CSE had a significant effect on the sensory properties (except for aroma) of the butter samples during the 60-day storage. The best color, flavor, and overall acceptance scores were assigned to the treatments containing 0.1%-0.5% CSE compared to the control sample. It could be concluded that adding 0.1% and 0.25% CSE to refrigerated and pasteurized butter can retard microbial spoilage and improve its sensory properties at the same time.
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  • 文章类型: Journal Article
    在包括埃及在内的热带和亚热带地区,半熟牛肉午餐会在环境温度下储存期间可能会发生恶化的变化。这项研究是在埃及的一家肉类工厂中进行的,目的是克服在37°C或更高的夏季不利温度下在杂货店展示的变质未售出牛肉午餐会带来的经济损失。使用不同的防腐剂应用了十种方法,包括亚硝酸钠,Nisin,山梨酸钾,和有机酸盐(乳酸钠的组合,乙酸钠,和双乙酸钠)。此外,产品在不同温度下烹饪,并在37°C下储存21天,在此期间的保质期,微生物质量,pH值,和感官属性进行了调查。到存储的第21天,午餐会含有50毫克/千克的亚硝酸钠,25mg/kg乳酸链球菌素,和1000毫克/千克有机酸盐,当在92°C的最终核心温度下烹饪时,表现出有氧平板计数的减少,厌氧板计数,乳酸菌计数,霉菌和酵母计数分别为4.32、3.54、3.47和1.89log10CFU/g,分别,与对照组相比。在这种处理的最终产品中还保持了感官属性和pH。无产品退货,避免经济损失。这项研究提出了一种新颖的方法,用于解决半干制午餐香肠和类似肉制品中发生的恶化变化的主要问题,这些问题需要拒绝,并造成巨大的经济损失。特别是在世界上的热带和半热带地区,这些地区存在类似的问题,即气候温度高,能源或技术资源的可用性低。
    Semidry beef luncheon may undergo deteriorative changes during storage at ambient temperatures in tropical and subtropical regions including Egypt. This study was conducted in a meat plant in Egypt with the aim of overcoming the economic losses from the returns of spoiled unsold beef luncheon displayed in grocery stores at adverse summer temperatures of 37 °C or more. Ten approaches were applied using different preservatives, comprising sodium nitrite, nisin, potassium sorbate, and organic acid salts (a combination of sodium lactate, sodium acetate, and sodium diacetate). In addition, the product was cooked at different temperatures and was stored for 21 days at 37 °C, during which time the shelf life, microbial quality, pH, and sensory attributes were investigated. By Day 21 of storage, the luncheon contained 50 mg/kg sodium nitrite, 25 mg/kg nisin, and 1000 mg/kg organic acid salts and, when cooked at a final core temperature of 92 °C, exhibited reductions in aerobic plate count, anaerobic plate count, lactic acid bacterial count, and mold and yeast counts by 4.32, 3.54, 3.47, and 1.89 log10 CFU/g, respectively, when compared with the control. The sensory attributes and pH were also maintained in the final products of such treatment, with no product return and the avoidance of economic loss. This study presents a novel approach for solving the major problem of the deteriorative changes that occur in semidry luncheon sausage and similar meat products which require rejection with a huge economic loss, especially in tropical and semitropical areas of the world that have similar problems of high climatic temperatures and a low availability of energy or technological resources.
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  • 文章类型: Editorial
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  • 文章类型: Editorial
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  • 文章类型: Journal Article
    肉变色,脂质氧化,不良质地是巴沙鱼片在储存过程中不可避免的现象,这反过来限制了它们的出口,并降低了消费者的接受度。此外,消费者对高质量的要求不断提高,最小处理,保质期延长的现成鱼片是一个巨大的挑战,特别是生活方式的改变。因此,这项研究旨在提高质量,脂质稳定性,脂肪酸谱,和使用胃蛋白酶在4°C下冷藏15天的Basa鱼片的脂质营养质量指数(LNQI)(E,0.1%),迷迭香油(R,0.5%),柠檬酸(CA,0.5%),及其组合(0.1%E+0.5%R;0.1%E+0.5%CA;和0.1%E+0.5%R+0.5%CA)。我们的结果表明,所有处理的样品都表现出蛋白质含量的显着增加,脂肪含量显著下降,pH值显著降低,总挥发性碱氮(TVBN),硫代巴比妥酸(TBA),游离脂肪酸,和剪切力(SF)值与对照组相比。此外,感官评分显著改善,颜色稳定性,脂肪酸谱,LNQI,观察所有处理样品的微生物质量。这种发现在用胃蛋白酶混合物处理的样品中更为明显,迷迭香,和柠檬酸(TVBN:2.04vs.6.52mg%;TBA:0.40vs.2.68mg丙二醛/Kg;SF:8.58vs.19.51Kgf)。根据获得的结果,所有经过处理的Basa鱼片样品的保质期都有延长,特别是在用胃蛋白酶混合物处理的样品中,迷迭香,和柠檬酸与对照样品相比(15天对10天)。此外,桉树脑,樟脑,异脑片,α-pine烯是迷迭香的主要成分,具有很好的抗氧化和抗菌活性。总之,胃蛋白酶的混合物,迷迭香,柠檬酸可以很容易地应用于海鲜行业和家庭水平,以提供高质量的即食鱼片,具有极大的健康益处。
    Meat discoloration, lipid oxidation, and undesirable texture are inevitable phenomena in basa fish fillets during storage, which in turn limits their exportation as well as decreases consumer acceptability. In addition, increasing consumers\' requirements for high-quality, minimally processed, and ready-to-cook fish fillets with an extended shelf-life is a great challenge, particularly with lifestyle changes. Accordingly, this study aimed to improve the quality, lipid stability, fatty acid profile, and lipid nutritional quality indices (LNQI) of basa fish fillets during chilling storage at 4 °C for 15 days using pepsin enzyme (E, 0.1%), rosemary oil (R, 0.5%), citric acid (CA, 0.5%), and their combination (0.1% E + 0.5% R; 0.1% E + 0.5% CA; and 0.1% E + 0.5% R + 0.5% CA). Our results revealed that all treated samples exhibited a significant increase in protein content, a significant decrease in fat content, and a marked reduction in pH, total volatile base nitrogen (TVBN), thiobarbituric acid (TBA), free fatty acids, and shear force (SF) values in comparison to control ones. Moreover, significant improvements in sensory scores, color stability, fatty acid profile, LNQI, and microbial quality of all treated samples were observed. Such findings were more pronounced in samples treated with a mixture of pepsin, rosemary, and citric acid (TVBN: 2.04 vs. 6.52 mg%; TBA: 0.40 vs. 2.68 mg malonaldehyde/Kg; and SF: 8.58 vs. 19.51 Kgf). Based on the obtained results, there was an extension for the shelf life of all treated basa fish fillet samples, especially in samples treated with a mixture of pepsin, rosemary, and citric acids when compared with the control samples (˃15 days versus 10 days). Additionally, eucalyptol, camphor, isoborneol, and α-pinene are the main components of rosemary, with great antioxidant and antimicrobial activity. In conclusion, the mixture of pepsin, rosemary, and citric acid can be applied easily in the seafood industry and at the household level to provide ready-to-cook fish fillets of high quality with great health benefits.
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  • 文章类型: Journal Article
    Artisanal萨拉米香肠是在小规模生产工厂生产的,缺乏完全自动化可能会导致食物内在特性的更高可变性。本研究的目的是评估从六批意大利手工生产的有机萨拉米香肠中收集的480个样品中,物理化学参数的批次间和批次内变异性及其对微生物质量和食源性病原体发生的影响。在填充室的桌子表面上发现了相对较高的细菌总数(TBC)(4.29±0.40logcfu/cm2)。第2批和第5批TBC的肉混合物中肠杆菌科的高负荷与细菌病原体的较高发生率相关。在成熟过程中,水活度(aw)和pH值分别低于0.86和5.3。在成熟和加工环境期间,从萨拉米肉混合物中收集了6种金黄色葡萄球菌和4种单核细胞增生李斯特菌分离物。共有126株肠杆菌科细菌在物种水平上进行了表征,大肠杆菌,肺炎克雷伯菌,阴沟肠杆菌,和从最终产品中分离的freundii柠檬酸杆菌。结果表明,在填充过程中原材料的卫生和处理方面,生产的第一步的相关性,特别是当最终产品的物理化学参数没有达到代表食源性病原体的障碍的值时。
    Artisanal salami is produced in small-scale production plants, where the lack of full automation might result in higher variability in food intrinsic properties. The aim of the present study was to evaluate the inter- and intra-batch variability in physicochemical parameters and its impact on microbial quality and occurrence of foodborne pathogens on 480 samples collected from six batches of an artisanal Italian production of organic salami. Relatively high total bacterial counts (TBC) were found on the surface of the table in the stuffing room (4.29 ± 0.40 log cfu/cm2). High loads of Enterobacteriaceae in the meat mixture of batch 2 and TBC in batch 5 were associated with a higher occurrence of bacterial pathogens. During ripening, water activity (aw) and pH failed to reach values lower than 0.86 and 5.3, respectively. Six Staphylococcus aureus and four Listeria monocytogenes isolates were collected from the salami meat mixture during ripening and the processing environment. A total of 126 isolates of Enterobacteriaceae were characterized at a species level, with Escherichia coli, Klebsiella pneumoniae, Enterobacter cloacae, and Citrobacter freundii isolated from the final products. Results suggest the relevance of first steps of production in terms of the hygiene of raw materials and handling during stuffing procedures, especially when the physicochemical parameters of the final products do not reach values that represent hurdles for foodborne pathogens.
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