Effectiveness of Dipping with Phosphate, Lactate and Acetic Acid Solutions on the Quality and Shelf-life of Pork Loin Chop

Extending the shelf‐life of pork loin chops by dipping in 2% acetic acid (AA), 10% sodium lactate (SL), or 10% trisodium phosphate (TSP), compared to the undipped control (CONT), was demonstrated. TSP had the highest pH and water‐holding capacity. However, TSP had a dry and dark visual appearance on the loin chop surface, while AA was similar to pale, soft, and exudative (PSE) pork. CONT and SL had obvious putrid odor with TPC exceeding 10⁷ CFU/g at d 6 and d 9, respectively. Pork loin chops dipped in 10% sodium lactate solution resulted in better visual appearance and lower microbial counts, suggesting a possible extension of the shelf‐life to 6 d under refrigeration.     

不同工艺条件对猪胴体和冷却猪肉微生物去污染效果的影响

调查了冷却猪肉生产企业现有生产工艺下微生物污染的状况 ;研究了对现有生产工序 (冲淋工序、冷却工序 )采用新的处理工艺 ,包括水冲洗、乳酸喷淋、冷分割以及联合处理等对猪胴体和冷却猪肉微生物去污染的效果。结果表明 ,在现有生产工艺下 ,冷却猪肉微生物污染随季节发生显著变化 ,且达不到HACCP体系微生物控制要求 ;水冲淋、乳酸喷淋、冷分割单独处理或联合处理 ,均有显著的微生物去污染效果。如果采用热分割 ,劈半后冲洗 1min ,乳酸喷淋 1min ,则微生物去污染效果显著 ,可基本达到HACCP对微生物控制要求。如果采用冷分割 ,劈半后冲洗 1min ,冷却 2 4h ,再次采用冷分割效果较好 ,冷却猪肉可基本达到HACCP对微生物控制要求 ;若劈半后冲洗 1min ,乳酸喷淋 1min ,冷却 2 4h则可完全达到HACCP对微生物控制要求。     

Consumer Evaluation of Raw and Fried Chicken After Washing in Trisodium Phosphate or Lactic Acid/Sodium Benzoate Solutions

Whole raw, chickens (180) were washed in tapwater (control), 12% trisodium phosphate (TSP), or 0.5% lactic acid/0.05% sodium benzoate (LB). Consumer panelists evaluated raw, treated, whole chickens as well as fried breast and thigh pieces. TSP and LB solutions did not affect (P < 0.05) external color, texture, flavor, moistness, or overall acceptability of fried chicken or consumer purchase intent. Evaluation of raw chickens 90 min after treatment with LB or after 7 days storage at 1°C revealed that overall acceptability, color and purchase intent were lower compared to controls. Sensory quality of raw chickens was not adversely affected by TSP. We concluded that 12% TSP or 0.5% lactic acid/0.05% sodium benzoate solutions have good potential for dips to sanitize chickens intended for frying before presentation to consumers.     

壳聚糖复合磷酸钠处理对苹果青霉病的影响及部分机理

以金冠苹果为试材,研究不同浓度壳聚糖复合0.5 mg/mL磷酸钠浸泡处理对损伤接种扩展青霉(Penicilli-um expansum)果实病斑扩展的影响,研究最佳复合处理对果实抗氧化酶活性及苯丙烷途径关键酶活性和产物积累的影响.结果表明,1.0％壳聚糖复合磷酸钠处理对果实青霉病的控制效果最佳,处理显著降低病斑直径...     

冻猪肉加工中沙门氏菌的综合控制

强调了沙门氏菌对人畜的危害性和分布的广泛性,着重阐述了生猪屠宰加工分割、包装、冷藏运输各工序对沙门氏菌的综合防控措施.     

Physicochemical and Sensory Qualities of Fresh Pork Chops as Affected by Phosphate, Ascorbate or Sorbate Dipping Prior to Irradiation

Fresh pork chops were dipped for a target absorption of 0.5% sodium tripolyphosphate (STPP), 550 ppm sodium ascorbate (SA), or 0.1% potassium sorbate (PS) prior to irradiation (1.0 kGy). Untreated pork chops, both irradiated and unirradiated, were used as controls. Dipping with STPP decreased drip loss and improved color and lipid stability of irradiated chops and resulted in better tenderness and juiciness scores than undipped, irradiated samples. Also, STPP treated chops had similar or better physicochemical and sensory properties than untreated (no irradiation, no dipping) controls. Dipping with SA or PS had little effect compared with STPP, but improved some sensory qualities.     

南京地区猪肉源中沙门氏菌分子分型及耐药性分析

沙门氏菌是造成我国食源性疾病的常见细菌之一,也是肉类消费过程中密切监测的重点对象。在2018年~2021年期间,共计采集了南京市545份猪肉源食品样本,利用选择性培养法分离得到44株沙门氏菌,采用血清学方法和分子生物学方法（MLST）对其进行分型鉴定,并分析其耐药性。结果表明,市售样本中共计检出44株沙门氏菌,平均检出率为8.07%,其中内脏样本检出率相对最高（检出率为30.49%）;血清型分析表明,检出的菌株中以鼠伤寒沙门氏菌（Salmonella typhimurium）、罗森氏沙门氏菌（Salmonella rissen）、德尔卑沙门氏菌（Salmonella derby）和伦敦沙门氏菌（Salmonella london）4种血清型沙门氏菌最为常见;基因分型表明,ST19型为猪肉源中优势沙门氏菌株,占比为20.45%;检出的沙门氏菌中,38株菌株对四环素具有明显耐药性,占全部检出菌株的86.36%,而对头孢他啶、头孢噻肟和头孢西丁的耐药不超过10%。此外,对检出的1株多重耐药性沙门氏菌耐药基因分析发现,共筛查出了包括7大类抗生素及与耐药相关的基因。该实验详细分析了南京市场猪肉源食品中沙门氏菌污染状况,也为后期沙门氏菌的综合防治提供了理论依据。     

肉牛屠宰过程中的减菌技术研究进展

为了减少冷却肉的初始菌落数,延长其货架期并提高其安全性,众多学者对畜禽胴体及冷却肉减菌技术进行了研究。因此,本文对近年来肉牛屠宰过程及冷却牛肉生产过程中应用的减菌技术研究进展进行概述,总结基于物理方法减菌的胴体修整及清水冲洗、热除菌、紫外线杀菌和低温等离子体杀菌等措施,以及基于化学方法减菌的有机酸喷淋、过氧乙酸喷淋等措施。通过比较分析每种方法的减菌效果及优缺点,初步得出清水冲洗与乳酸喷淋的复合减菌方法是既有效又经济的牛胴体减菌措施的结论。通过本文的总结和概述,期望可以为肉牛屠宰企业合理地选择减菌措施提供参考。     

生鲜猪肉中沙门氏菌的分离、鉴定及耐药性检测

调查本地区生鲜猪肉中沙门氏菌的污染情况及耐药性情况,为进一步对肉及肉制品中耐药性沙门氏菌的风险评估奠定基础。采集超市和集贸市场的生鲜猪肉,采用实时荧光定量PCR对生鲜猪肉中沙门氏菌污染进行初筛,然后根据沙门氏菌检验国家标准进行分离鉴定,并对分离到的沙门氏菌进行耐药性检测。结果从83份肉样中分离到21株沙门氏菌,沙门氏菌检出率为25.3%。21株沙门氏菌中有7株对11种抗生素中的至少一种产生耐药性,耐药率33.3%。结果表明本地区生鲜猪肉微生物污染较为严重,沙门氏菌检出率较高且四环素耐药严重;另外在菌落总数和沙门氏菌检出率方面冷却肉的质量好于热鲜肉,超市和集贸出售的肉的质量无显著差异。     

Microbial and Quality Characteristics of Pork Cuts from Carcasses Treated with Sanitizing Sprays

Pork carcasses were sprayed with 1.5% acetic, citric, or lactic acid. Loins were vacuum packed and stored at 0–2°, chops were cut periodically from loins and stored at 2–4°. Acetic and citric acids decreased (P<0.05) aerobic plate counts (APC) and total coliforms in loins for 14 days. Species of Salmonella, Yersinia, and Campylobacter were found on 0, 6, and 5% of samples. Lisreria spp were detected on 69% of loins and on 33% of chops. The sanitizing treatments were of relatively limited effectiveness for long term storage. No pH, TBA or sensory quality differences were observed.     

Loop-Mediated Isothermal Amplification (LAMP) for the Rapid and Sensitive Detection of Salmonella Typhimurium from Pork

ABSTRACT: Loop-mediated isothermal amplification (LAMP) is a novel molecular detection method that is more rapid and simpler than PCR. Products can be detected by turbidity using one temperature without the need for expensive PCR equipment. Our objective was to sensitively detect Salmonella Typhimurium from pork products within 1 d using the LAMP assay. Pork chop and pork sausage samples (25 g) were inoculated with high (10⁸ to 10⁶ CFU) and low (10⁵ to 10⁰ CFU) inocula of S. Typhimurium. Serial dilutions in phosphate buffered saline were plated on XLT4 agar either immediately or after selective preenrichment in tetrathionate broth (225 mL) for 10-h at 37 °C. Nucleic acid was extracted using the TRIzol^® method from 1-mL samples. The LAMP assay using 6 specific invA gene primers and Bst DNA polymerase reaction mix was carried out at 62 °C for 90 min in a waterbath. Turbid products were detected visually and by agarose gel electrophoresis. Improved Salmonella detection at 10² CFU/25 g for both pork chop and sausage was obtained after 10-h enrichment and 10⁶ CFU/25 g without enrichment for both products. This assay can detect Salmonella from pork within 1 d, significantly faster than traditional methods that take >5 d. This method shows tremendous potential for routine diagnostics and monitoring of Salmonella by the pork industry. Practical Application: The novel loop-mediated isothermal amplification (LAMP) assay is a rapid, specific, and sensitive method that has potential application for routine diagnostics of Salmonella from pork products. The isothermal method does not require expensive equipment such as a PCR thermocylcer but only a simple waterbath for amplification within 90 min. Detection is even simpler by visual eye or turbidimeters that are less expensive than fluorescent spectrophotometers or real-time PCR machines. All these advantages make it a practical approach for routine use by processing industries to rapidly detect Salmonella in their environment and to implement appropriate control strategies. To improve detection sensitivities, preenrichment followed by selective enrichment may be necessary. Even so, the entire assay can be completed at the most within two 8-h working shifts.     

含磷酸盐的香辛料液对猪肉品质的影响

本文研究了含磷酸盐的香辛料液对猪肉嫩度和感官品质的影响。将肉样分成4个组,分别注射含不同浓度磷酸盐(0.0%,0.2%,0.3%,0.4%)的香辛料液。肉样注射后在4℃冷藏72h,测定嫩度,pH值,成品率和感官指标,结果表明:试验组的嫩度、成品率和风味明显高于对照组(P<0.05),且磷酸盐浓度越高,效果越明显,但各组间猪肉颜色没有呈现出明显差异。研究表明将磷酸盐溶解于香辛料液中注入猪肉可以改善肉的品质。     

宰前管理和屠宰工艺对宰后猪肉品质的影响

猪肉品质是人们对猪肉多种质量特性的综合评价。影响猪肉品质的因素诸多,本文主要从生猪宰前管理、屠宰工艺、宰后处理等环节进行分析,综述了近年来国内外学者研究成果,从而为猪肉生产各环节及关键点进行有效控制,降低PSE肉发生率及生产出安全、优质的猪肉产品相关科学研究提供理论依据。     

磷酸三钠对番茄上沙门氏菌的杀灭作用研究

研究了磷酸三钠溶液(TSP)对成熟绿种番茄表皮上和梗洼木栓化核组织中的沙门氏菌S.monte-video的杀灭作用。浸于1%TSP溶液15s可使表皮上的沙门氏菌显著减少(P<0.05);将番茄浸于10%～15%TSP溶液15s～2min可使表皮上的沙门氏菌完全杀灭;浸于4%～15%TSP溶液15s～2min可使核组织中的沙门氏菌显著减少,但最多只可减少2个对数级。在果实的后熟期间,番茄的色泽和色度深浅不受TSP浸洗处理的影响。使用磷酸三钠溶液做为番茄加工的浸洗消毒剂有着较好的使用效果。     

热处理对猪肉食用品质的影响

为了研究热处理对猪肉食用品质的影响,分别对猪肉背最长肌加热至中心温度25、50、60、80、100℃,然后测定不同温度处理对猪肉蒸煮损失、剪切力值、形状、色度、pH 值的影响。结果表明：猪肉的蒸煮损失、剪切力和pH 值随着热处理温度的升高而增加;肉块形状发生短缩;色泽从红色变为白色、灰白色。     

猪肚罐头的研制

本文阐述猪肚罐头的制作技术 ,为猪肚的利用开发了一条新途径     

超声波处理对猪肉腌制效果的影响

研究超声波处理对猪肉腌制效果的影响.将猪背脊肉(每个样本50g)浸入浓度为10%食盐溶液中,采用功率为300W、频率为40kHz的超声波,分别处理0、20、40、60、80、100、120 min;再4℃静置腌制,共腌制12 h(从浸入食盐溶液开始计时).通过测定猪肉中氯化钠含量、蛋白质含量、猪肉嫩度及保水力,比较超声波处理组与对照组各性能的优劣.结果表明,在总腌制时间相同的情况下,随超声波处理时间延长,腌制速度、蛋白质的溶出、肉的嫩度都能得到提高,并在100 min～120 min阶段急剧变化;而保水性在处理60 min时最好.超声波处理技术能较好地改善猪肉的腌制效果.     

Evaluation of a Polymerase Chain Reaction–Based System for Detecting Salmonella Species from Pork Carcass Sponge Samples

Pork carcass sponge samples (n = 230) collected from 10 Taiwanese slaughter plants were screened for Salmonella using 2 methods: BAX® for Screening/Salmonella, a polymerase chain reaction‐based detection system and a culture method using SM‐ID agar as the selective plating medium. The BAX method identified 14 samples as positive for Salmonella. The 8 samples identified as Salmonella‐positive by the SM‐ID method were also BAX‐positive. Inoculation studies showed BAX detected Salmonella in samples having initial 1.4 × 10¹ cfu/mL Salmonella inoculum prior to the enrichment process in the presence of 3.0 × 10⁶ cfu/mL of non‐Salmonella florae. BAX provides a rapid screening alternative to the culture method for Salmonella detection.     

Microbiological Properties of Pork Cheek Meat as Affected by Acetic Acid and Temperature

Our objective was to determine the effect of acetic acid (AA) and temperature in inhibiting Salmonella typhimurium, aerobic plate counts (APCs) and total coliforms on pork cheek meat. Compared with initial APCs of control cheeks, a reduction in log₁₀ CFU/cm² APC by more than 78.6% was found in all samples that were treated with 20 and 40° acetic acid (P < 0.05). Additionally, total coliforms for acidtreated cheeks were lower for both AA treatments (P < 0.05). Cheeks (n = 10/treatment) were also sprayed in a commercial pork slaughter facility carcass wash with 2% AA (25°) and compared to control (non-treated) cheeks. The incidence of Salmonella decreased by 67% for acid-treated cheeks (P < 0.05). A significant decrease in APCs and coliforms occurred for the acid-treated cheeks (P < 0.05).     

乳酸、ASC、CPC及TSP对冷却猪肉的保鲜作用的研究

比较了用乳酸、酸化亚氯酸钠(ASC)、氯化十六烷基吡啶(CPC)及磷酸三钠(TSP)配制的保鲜液对冷却猪肉的保鲜效果。对猪肉进行浸泡处理后在5℃冷藏条件下存放7d,分别在第0、3、5、7d对经处理的样品及对照样品进行微生物指标、TVB-N等方面的测定,发现这几种保鲜液对猪肉都有一定的抑菌保鲜效果,其效果由好到坏依次为:乳酸≈CPC>TSP>ASC2>ASC1。