如皋火腿中肉糖葡萄球菌RG-10产硝酸盐还原酶条件的优化

硝酸盐还原酶可以将硝酸盐还原为亚硝酸盐,对肉制品色泽和风味形成尤为重要。分析从如皋火腿中分离得到的4株葡萄球菌的产硝酸盐还原酶特性,研究菌株产硝酸盐还原酶的影响因素。以高产硝酸盐还原酶肉糖葡萄球菌RG-10为研究对象,通过正交试验对其产硝酸盐还原酶条件进行优化,并对优化条件进行验证,各因素对肉糖葡萄球菌RG-10产硝酸盐还原酶的影响程度顺序为Na Cl浓度温度时间KNO3浓度。确定肉糖葡萄球菌发酵产硝酸盐还原酶的最佳发酵条件为时间18 h、Na Cl浓度2.5%、KNO3浓度0.2%、温度42℃,此条件下的硝酸盐还原酶酶活为482 U/mg蛋白。     

天然草莓红色素应用到香肠中的工艺条件优化

将天然草莓红色素应用到香肠中,观察其对香肠感官评价和色泽的影响。选用天然草莓红色素的添加量、煮制温度、煮制时间进行单因素和正交试验对香肠的制备工艺进行优化。结果表明,最佳工艺条件为天然草莓红色素的添加量0．01％、煮制温度85℃、煮制时间40min。     

抗坏血酸、烟酸和pH对香肠发色和色素稳定性的影响

通过在香肠的制作过程中添加不同剂量的抗坏血酸、烟酯和调节ｐＨ值,研究肉块发色和香肠色素贮藏稳定性的变化,结果表明,抗坏血酸的添加能加快发色速度,提高发色效果（Ｐ＜０．０５）。添加量超过８００ｍｇ／ｋｇ时效果不再明显（Ｐ＞０．０５）,但对色素的保持,大剂量（１０００ｍｇ／ｋｇ）效果明显。烟酸具有一定的助色效果,但单独使用效果不理想,和５００ｍｇ／ｋｇ以上的抗坏血酸一起使用作用显著（Ｐ＜０．０５）,烟酸对香肠的色素稳定性无好的影响（Ｐ＞０．０５）。低的ｐＨ值可加速发色,缩短发色时间,但对色素的保持以及产品的质地有不良影响（Ｐ＜０．０１）。     

影响香肠pH值的因素

通过添加不同水平的Vc和贮藏时间，温度的变化，测定香肠中的pH值的大小，结果表明：Vc使香肠中pH值降低（P＜0．05）；贮藏时间长，pH值先减小第32d后又略有增加；贮藏温度对pH值影响差异不显著（P＞0．05）。     

茶多酚对香肠发色效果影响的研究

为研究茶多酚对香肠发色效果的影响,将0.015%的茶多酚添加至香肠中,对香肠颜色感官评分、发色率、色泽亮度L＊、红度a＊、黄度b＊和香肠亚硝酸钠残留量进行测定,并分析以上参数之间相关性。实验表明,添加0.015%的茶多酚处理样,香肠的颜色感官评分、发色率、色泽亮度L＊、红度a＊的变化上都优于对照样,且呈现出更少的亚硝酸盐残留量,特别在发酵贮藏末期（35d）,较对照样减少亚硝酸盐残留量高达28%。因此可以认为茶多酚对香肠有良好的发色效果。     

降低香肠中硝酸盐添加量及其残留物的探讨

本文介绍了在香肠中采用真空包装稳定香肠的色泽,尽量降低硝酸盐添加量及亚硝酸根残留量、提高香肠的卫生质量及货架寿命。通过对香肠中亚硝酸根及硝酸根的监测,提出硝酸盐的残留问题。香肠是我国一种传统的肉制品,一直深受广大消费者欢迎。当前、香肠生产过程中多采用硝酸盐或亚硝酸盐作为发色剂、它们不仅能使肉制品产生极好色泽,而且能抑制肉毒杆菌、保证肉制品的后熟风味。但现在发现,加硝处理过的肉制品有亚硝胺类化合物残留,而亚硝胺类化合物能持续地在特定种类动物的器官诱发癌症,是一种强致癌物,故国家通过制订一系列的食品卫生标准,限制硝酸盐或亚硝酸盐在香肠中的添加量及亚硝酸根残留量。鉴于此、肉品加工行业,一方面尽量降低硝酸盐或亚硝酸盐的用量,配合使用抗坏血酸钠,L-谷氨酸钠,δ-葡萄糖醛酸内酯、焦磷酸钠、多磷酸钠等混合助色剂,使盐肠呈现较好的颜色、大幅度降低亚硝酸根残留量。另一方面努力研究不加硝酸盐或亚硝酸盐的腌制法,并取得了一定的进展。笔者对香肠加硝发色以及色泽的稳定进行了一系列试验,以求以较少的硝量、较低的残留达到较好的发色效果,并通过对香肠中硝酸盐与亚硝酸盐的监测,提出硝酸盐的残留问题。     

大白菜贮藏过程中硝酸盐和亚硝酸盐含量变化分析

在不同贮藏温度（0、10、20 ℃）、贮藏方式（未包装、0.04 mm PE保鲜袋包装）条件下贮藏大白菜（Brassica rapa pekinensis）16 d后,采用高效液相色谱法测定大白菜中硝酸盐和亚硝酸盐含量的变化。结果表明,在不同贮藏温度和贮藏方式条件下,硝酸盐和亚硝酸盐的含量随着贮藏时间的延长均呈现先增加、后降
低、再上升的趋势,其中硝酸盐的含量在整个贮藏期间,均在低于432 mg/kg的安全食用范围内;亚硝酸盐含量在20 ℃贮藏条件下贮藏7 d即超过了4 mg/kg的安全摄入量,而其他贮藏条件均在安全食用范围内。大白菜中硝酸盐与亚硝酸盐的含量在贮藏过程中随贮藏温度的降低而显著减少,到贮藏末期（16 d时）20 ℃和10 ℃贮藏大白菜中硝酸盐含量分别是0 ℃贮藏的1.2 倍和1.1 倍,亚硝酸盐含量分别是0 ℃贮藏的1.4 倍和1.2 倍。PE保鲜袋包装有助于减少大白菜在中、低温（10、0 ℃）贮藏中硝酸盐与亚硝酸盐的含量,但在高温（20 ℃）贮藏中其含量增加。因此,建议贮藏大白菜时最好采用PE保鲜袋包装和0～10 ℃的贮藏温度,以保证其硝酸盐和亚硝酸盐含量不超标。     

贮藏温度及时间对羊肉发酵香肠贮藏特性的影响

为明确不同贮藏温度及贮藏时间对羊肉发酵香肠贮藏特性的影响,测定4℃及20℃贮藏4周过程中发酵香肠理化及微生物指标的变化。结果显示:4℃贮藏可以显著减少羊肉发酵香肠脂质的氧化(thiobarbituric acid reactive substances,TBARS)与挥发性盐基氮(total volatile base nitrogen,TVB-N)的产生、水分活度(water activity,Aw)的下降及葡萄球菌数量的减少(P0.05);贮藏时间的延长显著影响发酵香肠的TBARS、TVB-N、Aw、pH值、色泽、质构等理化特性及葡萄球菌的数量(P0.05);不同贮藏温度及贮藏时间对乳酸菌数量均无显著影响(P0.05);贮藏温度及贮藏时间对TBARS、TVB-N、Aw、pH值、L*值及葡萄球菌数有显著交互作用(P0.05)。综合以上结果表明,在发酵香肠贮藏4周时间内,与20℃相比4℃贮藏可以更好的保持发酵香肠的品质特性及安全性;随着贮藏时间的延长,发酵香肠的品质整体呈下降趋势。     

汉麻籽油自氧化及抗氧化性能的研究

采用Schaal烘箱法,以过氧化值（POV）为指标,研究温度、时间对汉麻籽油自氧化过程的影响及添加抗氧化剂对汉麻籽油抗氧化性能的影响。结果表明,温度、时间对汉麻籽油的自氧化过程有显著影响,且温度的影响更明显;叔丁基对苯二酚（TBHQ）对汉麻籽油具有较好的抗氧化性能,柠檬酸和异VC对TBHQ与丁基羟基茴香醚（BHA）复配的复合抗氧化剂均表现出较强的协同抗氧化性能,且柠檬酸的协同抗氧化性优于异VC;添加0．02％TBHQ＋0．005％BHA＋0．01％柠檬酸或0．02％TBHQ＋0．005％BHA＋0．01％异VC复合抗氧化剂,可使汉麻籽油在20℃下的预贮藏时间从4个月延长至11～13个月。     

芹菜粉对天然中式香肠颜色影响及工艺优化的研究

天然中式发酵香肠是不添加人造着色成分、化学防腐剂或任何其他人造或合成成分的一种产品。本文以芹菜粉、产硝酸还原酶的木糖葡萄球菌和肉糖葡萄球菌作为天然配料,以中式香肠的红度值a和亚硝酸盐残留量为指标,通过单因素实验确定了四因素(接种量、菌种配比、发酵温度和发酵时间)的优工艺参数的基础上,采用正交实验L9(34)的方法,确定最优的发酵工艺参数条件为:A1B3C2D2,即发酵时间为30h,发酵温度为30℃,发酵菌株接种量为107cfu/g,发酵菌种配比采用木糖葡萄球菌:肉糖葡萄球菌=1:2。     

复合保水剂及异抗坏血酸钠对乳化肠乳化性的影响

研究复合保水剂芋头、卡拉胶、大豆分离蛋白和异抗坏血酸钠对乳化肠保水性与保油性的影响,以总压出汁液率、蒸煮损失、保油性和感官评定为指标,通过单因素试验和中心组合试验,运用响应面法优化工艺参数,建立多元二次回归方程,优选出乳化肠的保水性与保油性的最佳工艺参数。结果表明芋头添加量7.02%、卡拉胶添加量0.51%、大豆分离蛋白添加量5.13%、异抗坏血酸钠添加量0.06%时,与预测值基本一致。     

不同乳酸菌发酵剂对发酵红肠品质的影响

为研究乳酸菌发酵对红肠品质的影响,将发酵技术应用于本无发酵工艺的红肠制品中,筛选出能够提高红肠品质的乳酸菌发酵剂。分别将常应用于发酵肉制品的7 种商业乳酸菌发酵剂（木糖葡萄球菌＋戊糖片球菌（THM-17）、木糖葡萄球菌＋清酒乳杆菌＋类植物乳杆菌（PRO-MIX5）、木糖葡萄球菌＋肉葡萄球菌＋清酒乳杆菌（WBL-45）、木糖葡萄球菌＋戊糖片球菌＋植物乳杆菌（VHI-41）、木糖葡萄球菌＋戊糖片球菌＋植物乳杆菌（SHI-59）、肉葡萄球菌＋木糖葡萄球菌（WBX-43）和戊糖片球菌＋木糖葡萄球菌＋肉葡萄球菌＋乳酸片球菌（VBM-60））及8 种单菌（弯曲乳杆菌、戊糖乳杆菌、清酒乳杆菌-1、戊糖片球菌、木糖葡萄球菌、肉葡萄球菌、清酒乳杆菌-2、植物乳杆菌）以107 CFU/g的接种量接种至腌制后的肉馅中,拌馅灌肠后于35 ℃、80%湿度条件下发酵12 h,取样测定发酵后样品的乳酸菌数和细菌总数,再经干燥、蒸煮、烟熏、烘烤制得成品,测定其感官、pH值、色差、质构、亚硝酸盐、硝酸盐、生物胺及N-亚硝胺含量等指标。结果表明：15 种发酵剂中以木糖葡萄球菌和植物乳杆菌2 种乳酸菌发酵剂应用效果较好,所制得产品pH值分别为5.26和5.04,色泽美观,弹性适中,亚硝酸盐残留量（10.84、10.13 mg/kg）低,可显著抑制N-亚硝胺的形成（N-二甲基亚硝胺含量分别为1.29、2.51 μg/kg）,生物胺总量较低。由此说明,木糖葡萄球菌和植物乳杆菌能够显著提高红肠产品的安全品质。     

Effect of Sodium Erythorbate on Residual Nitrite, pH and Bacterial Growth in Liver Sausage Formulated with Different Levels of Mechanically Separated Pork

Some microbiological, chemical, and physical characteristics of liver sausage formulated with 0, 25, 50, and 75% mechanically separated pork (MSP), 156 ppm sodium nitrite and 0 or 550 ppm sodium erythorbate were studied during refrigerated storage (5°C, 6 days) and subsequent elevated-temperature holding (20–24°C, 48 hr). Growth of inoculated Clostridium sporogenes was inhibited by 156 ppm nitrite in all sausages even after 48 hr at 20–24°C, regardless of MSP level. Growth of aerobic mesophiles and facultative anaerobes at 20–24°C was also inhibited in sausage formulated with 156 ppm nitrite and 550 ppm erythorbate. Erythorbate addition and increased MSP levels resulted in higher Hunter a color values. Residual nitrite, pH values, and total iron content of liver sausage increased with increasing MSP content.     

白萝卜粉作为亚硝酸盐来源制备猪肉发酵干香肠

评价用白萝卜粉代替亚硝酸盐制备猪肉发酵干香肠的可行性。采用萨科VBM-60复合菌株作发酵剂，制备4组香肠：NC组（不添加硝酸盐或亚硝酸盐的阴性对照组）、PC组（添加150 mg/kg亚硝酸钠的阳性对照组）、R0.5组（添加0.5%白萝卜粉组）、R1组（添加1%白萝卜粉组）。研究加工和贮藏过程中白萝卜粉代替亚硝酸盐对猪肉发酵干香肠理化性质、微生物性质及感官性质的影响。结果表明：与添加150 mg/kg亚硝酸钠的对照组相比，添加0.5%白萝卜粉的香肠具有较高硫代巴比妥酸反应物值和较好外观，以及较低的pH值、红度值、硬度和咀嚼性，而水分含量、挥发性盐基氮值、亮度值、弹性、内聚性、菌落总数、组织状态、色泽和风味总体上差异不显著。在贮藏过程中，R0.5组香肠具有较高的亚硝酸盐含量和较低的乳酸菌数。R0.5组香肠在加工和贮藏结束时的亚硝酸盐含量分别为13.03 mg/kg和16.48 mg/kg，均符合国家规定的限定标准。结果表明，添加0.5%的白萝卜粉可在一定程度上作为天然亚硝酸盐来源，用于生产猪肉发酵干香肠。     

接种乳酸菌发酵剂对风干肠成熟过程中微生物群落动态变化及感官品质的影响

为研究乳酸菌发酵剂对风干肠成熟过程中微生物数量、微生物多样性及感官品质的影响,分别将SHI-59(木糖葡萄球菌+戊糖片球菌+植物乳杆菌)、WBL-45(木糖葡萄球菌+肉葡萄球菌+清酒乳杆菌)、PRO-MIX5(木糖葡萄球菌+清酒乳杆菌+类植物乳杆菌)复合型商业发酵剂接种到肉馅中,经过12?d的成熟过程生产发酵型风干肠,...     

BEHAVIOR OF STAPHYLOCOCCUS AUREUS IN REFRIGERATED AND FROZEN GROUND BEEF AND IN TURKISH STYLE SAUSAGE AND BROTH WITH AND WITHOUT ADDITIVES

Staphylococcus aureus 42E was inoculated into raw ground beef which was stored at 4C and -27C. Turkish style sausage and Brain Heart Infusion broth (BHIB), with and without additives were also inoculated with S. aureus and held at 4C. Samples of ground beef and sausage were examined for S. aureus, aerobic plate count and pH values. The numbers of S. aureus cells were decreased by 1.64 and 2.02 log units in ground beef held at 4C after 7 days and -27C after 7 weeks, respectively. A decrease in the number of S. aureus cells was observed in sausage and BHIB with addition of 0.5% trisodium phosphate (TSP), 78 mg/kg sodium nitrate, 78 mg/kg sodium nitrate plus 156 mg/kg sodium nitrate and 78 mg/kg sodium nitrite plus 0.5% TSP. Overall, sodium nitrite either alone or in combination with sodium nitrate was more effective on S. aureus and aerobic bacteria than TSP either alone or in combination with sodium nitrite.     

Use of deodorized yellow mustard powder to control Escherichia coli O157:H7 in dry cured Westphalian ham

Dry cured (uncooked) hams with low water activity and pH ≥5.6 seem a likely food vehicle for Escherichia coli O157:H7. In previous work, isothiocyanates produced from mustard glucosinolates by bacterial myrosinase-like activity converted deodorized mustard into a potent antimicrobial in dry sausage. In this study its value in controlling E. coli O157:H7 survival in Westphalian ham was investigated. Hams were inoculated with a 7.5 log cfu g(-1) cocktail of E. coli O157:H7, 4% or 6% (w/w) deodorized yellow mustard powder was surface applied and monitored 80 d for pathogen survival. In one trial to accelerate formation of isothiocyanate, a Staphylococcus (S.) carnosus meat starter culture was added to hams at 45 d (after salt equilibration). At 21 d, E. coli O157:H7 was reduced by 3 log cfu g(-1) on hams treated with mustard powder compared to only a 1 log cfu g(-1) reduction in the control. By 45 d, mustard powder caused a reduction of >5 log cfu g(-1)E. coli O157:H7, whereas it took 80 d for numbers in control hams to be similarly reduced. Although the commercial process used caused a 5 log cfu g(-1) reduction of E. coli O157:H7 in 80 d, 4% or 6% deodorized mustard accelerated this reduction and the S. carnosus starter culture may have contributed to the maintenance of this effect.     

Effect of Mechanically Separated Pork, Sodium Erythorbate and Sodium Nitrite Combinations on Clostridium sporogenes Survival and Growth in Liver Sausage

Liver sausage formulated with 50 or 75% mechanically separated pork (MSP), 75 or 150 ppm sodium nitrite and 0, 550 or 1100 ppm sodium erythorbate was examined for Clostridium sporogenes PA3679 survival and growth during refrigerated temperature storage (5°C, 6 days) and during subsequent exposure to elevated temperatures (22–24°C, 2 d). Sodium nitrite at 150 ppm inhibited clostridial growth in sausage held at 22–24°C, regardless of MSP content, if 550 ppm sodium erythorbate were also present. Sodium nitrite at 75 ppm combined with erythorbate at 550 and 1100 ppm did not inhibit C. sporogenes growth during simulated temperature mishandling of liver sausage. Residual nitrite decreased (P<0.05) with erythorbate addition but was unaffected by MSP.     

Development of Sausages Containing Mechanically Deboned Chicken Meat Hydrolysates

Pork meat sausages were prepared using protein hydrolysates from mechanically deboned chicken meat (MDCM). In terms of the color, compared to the controls before and after storage, the redness (a*) was significantly higher in sausages containing MDCM hydrolysates, ascorbate, and sodium erythorbate. After storage, compared to the other sausage samples, the yellowness (b*) was lower in the sausages containing ascorbate and sodium erythorbate. TBARS was not significantly different among the sausage samples before storage, whereas TBARS and DPPH radical scavenging activities were significantly higher in the sausagescontainingascorbate and sodium erythorbate, compared to the other sausage samples after 4 wk of storage. In terms of sensory evaluation, the color was significantly higher in the sausages containing MDCM hydrolysates, ascorbate, and sodium erythorbate, compared to the other sausage samples after 4 wk of storage. The “off‐flavor” and overall acceptability were significantly lower in the sausages containing MDCM hydrolysates than in the other sausage samples.     

Inhibition of Escherichia coli O157:H7 in ripening dry fermented sausage by ground yellow mustard

Compounds generated by the enzymatic hydrolysis of glucosinolates naturally present in mustard powder are potently bactericidal against Escherichia coli O157:H7. Because E. coli O157:H7 can survive the dry fermented sausage manufacturing process, 2, 4, and 6% (wt/wt) nondeheated (hot) mustard powder or 6% (wt/wt) deheated (cold) mustard powder were added to dry sausage batter inoculated with E. coli O157:H7 at about 7 log CFU/g to evaluate the antimicrobial effectiveness of the powders. Reductions in E. coli O157:H7 populations, changes in pH and water activity (aw), effects on starter culture (Pediococcus pentosaceus and Staphylococcus carnosus) populations, and effects of mustard powder on sausage texture (shear) were monitored during ripening. Nondeheated mustard powder at 2, 4, and 6% in dry sausage (0.90 aw) resulted in significant reductions in E. coli O157:H7 (P < 0.05) of 3.4, 4.4, and 6.9 log CFU/g, respectively, within 30 days of drying. During fermentation and drying, mustard powder did not affect P. pentosaceus and S. carnosus activity in any of the treatments. Extension of drying to 36 and 48 days reduced E. coli O157:H7 by >5 log CFU/g in the 4 and 2% mustard powder treatments, respectively. The 6% deheated mustard powder treatment provided the most rapid reductions of E. coli O157:H7 (yielding <0.20 log CFU/g after 24 days) by an unknown mechanism and was the least detrimental (P < 0.05) to sausage texture.