响应面法优化预调理火锅牛肉酶法嫩化工艺

针对预调理火锅牛肉的嫩化工艺,采用木瓜蛋白酶和中性蛋白酶进行复配,研究2种酶的复配比例、复合酶添加量及酶处理时间对牛肉持水力和硬度的影响.在单因素试验基础上,采用响应面优化设计对工艺条件进行优化,确定复配酶法嫩化最佳工艺条件为:木瓜蛋白酶和中性蛋白酶复配比例1:1.19、复合酶添加量0.085％、酶处理时间3.1?h,...     

不同嫩化方法对鹅肉品质的影响

采用自然熟化、木瓜蛋白酶和磷酸盐溶液处理鹅肉,对鹅肉的持水力、剪切力、p H值、氧化程度及肌纤维直径等品质指标进行研究。结果表明:自然熟化的嫩化效果不显著,木瓜蛋白酶和磷酸盐溶液处理可以大大提高鹅肉持水力,且以复合磷酸盐处理的鹅肉持水力最大。木瓜蛋白酶和不同磷酸盐嫩化处理的鹅肉剪切力均低于自然熟化的鹅肉。其中,浓度15 U/m L的木瓜蛋白酶处理的鹅肉剪切力最小。木瓜蛋白酶、焦磷酸钠、复合磷酸盐嫩化后鹅肉的p H值明显高于自然熟化处理。随着时间的延长,自然熟化的鹅肉其脂类氧化程度逐渐增加。木瓜蛋白酶和磷酸盐嫩化的鹅肉其脂类氧化程度低于自然熟化处理。其中,木瓜蛋白酶浓度为6 U/m L时鹅肉氧化程度最低。自然熟化过程中鹅肉肌纤维直径变化不显著,而木瓜蛋白酶和磷酸盐嫩化的鹅肉,随着嫩化液质量浓度的增大,肌纤维直径呈减小趋势。本研究结果为鹅肉的嫩化机理及鹅肉产品的开发利用提供了一定的理论依据。     

无花果蛋白酶与木瓜蛋白酶对牛肉嫩化的研究

以平均剪切力值为指标,研究了无花果蛋白酶嫩化牛肉的工艺条件。通过相差显微镜镜检比较了经同等活力浓度无花果蛋白酶与木瓜蛋白酶嫩化后老牛肉的细胞结构变化,结果表明:无花果蛋白酶嫩化10mm×10mm×25mm牛肉,适宜浓度为0.01%,有最小平均剪切力的条件是pH 7.0,预处理温度50℃,处理时间120min。与木瓜蛋白酶相比,无花果蛋白酶的嫩化效果更明显。     

木瓜蛋白酶对牛肉干品质的影响

以牛肉为主要原料,通过添加木瓜蛋白酶,改善牛肉干的持水率和质构,并用物性仪测定酶、嫩化温度和嫩化时间对其硬度、弹性、粘聚性、咀嚼度等质构特性的影响,通过实验得最佳工艺参数为:木瓜蛋白酶3mg/kg,嫩化温度55℃,嫩化时间3h.     

复合酶法协同超声波加工潮式卤鸭的工艺研究

采用超声波技术协同复合酶法对潮式卤鸭进行加工,以样品持水力、烹饪失水率及感官评分为指标,探讨复合蛋白酶(木瓜蛋白酶和菠萝蛋白酶)协同超声波处理对鸭肉的嫩化效果,并通过L9(34)正交试验优化工艺条件。结果表明:复合蛋白酶用量、超声功率、超声作用温度和超声作用时间对原料的持水力和烹饪失水率均有显著影响;最优工艺条件为复合酶用量0.3mg/mL、超声功率100W、超声作用温度35℃、超声作用时间30min,此条件下的持水力和烹饪失水率分别为92.09%与35.97%。     

响应面法优化木瓜蛋白酶嫩化牛肉工艺

为了提高牛肉品质,采用木瓜蛋白酶对牛肉嫩化工艺进行优化。以酶浓度、pH、处理温度、处理时间为考察因素,在单因素实验的基础上,采用Box-Behnken实验设计进行4因素3水平的响应面分析优化,确定最佳牛肉嫩化条件为:酶浓度0.07%,pH6.9,处理温度60℃,处理时间1.8 h。在此最佳嫩化条件下牛肉的持水率、弹性、内聚性及咀嚼性较对照组显著提高(p<0.01),烹饪失水率、剪切力和硬度较对照组显著降低(p<0.01),感官评价达到94.20分,较优化前提高了39.56%。初步机制研究发现木瓜蛋白酶可以降解牛肉肌纤维蛋白来提高牛肉嫩度。     

胰蛋白酶嫩化牛肉效果的研究

本实验采用TA-XT2i 质构仪,研究了胰蛋白酶处理对牛肉嫩度的影响,并采用L9(34)正交试验优化出最佳嫩化工艺。结果表明：胰蛋白酶的酶活、pH 值、处理温度、处理时间对牛肉的持水力、烹饪失水率、剪切力均有显著的影响。胰蛋白酶最佳嫩化条件为：酶用量100U/g(0.04%)、处理温度37℃、pH7.0、处理时间1.5h;或酶用量150U/g(0.06%)、处理温度20℃、pH7.0、处理时间1.5h。极差分析结果显示,各因素的显著性次序为：处理温度>胰蛋白酶用量>处理时间>pH 值。     

木瓜蛋白酶嫩化牛肉效果的研究

采用TA-XT2i质构仪,研究木瓜蛋白酶处理对牛肉嫩度的影响,对酶活力、pH值、处理温度、处理时间进行实验,并通过L9(34)正交试验选择出最佳嫩化工艺。结果表明：木瓜蛋白酶液的酶活、pH值、处理温度、处理时间对牛肉的持水力、烹饪失水率、剪切力均有显著的影响。木瓜蛋白酶最佳嫩化条件：酶用量20U/g(0.01%)、pH7.0、处理温度37℃、处理时间1.5h;或酶用量40u/g (0.02%)、pH7.0、处理温度20℃、处理时间1.5h。因素的显著性次序为：处理温度＞处理时间＞酶活＞pH值。     

软枣猕猴桃粗蛋白酶嫩化牛肉工艺优化及其嫩化机制

研究了软枣猕猴桃粗蛋白酶提取及对牛肉的嫩化效果,对酶用量、处理温度、处理时间对牛肉嫩化的影响进行了实验,并进一步通过L9(33)正交试验选择出最佳嫩化工艺并且通过测定其显微结构阐明其嫩化机制.结果表明:软枣猕猴桃粗蛋白酶的比活力为2098U/mg,对牛肉的剪切力、烹饪失水率和持水力均有影响,有较好的嫩化效果,通过正交试验确定软枣猕猴桃粗蛋白酶对牛肉嫩化的最佳工艺条件为酶用量0.05％、处理温度50℃、处理时间1.0h,影响因素次序为:处理温度＞酶用量＞处理时间,蛋白酶处理后的肉样和未处理的肉样相比肌原纤维直径变小,密度变大,小片化指数变大,其Z线断裂,肌间隙变大,肌间质增多,肌节长度变大,嫩度增加.     

嫩化和TG酶交联作用改善牛肉制品质构的初步研究

以传统的嫩化手段处理牛肉,通过转谷氨酰胺酶的交联作用再对牛肉原料进行二次处理,从肌肉蛋白的微观结构方面来改善牛肉品质,经菠萝蛋白酶、TG酶的复合作用后,以负重值、剪切力、系水力为主要检测指标,使用电镜观察肌肉组织,研究保障营养性、改善适口性、成型性、保水性的最佳工艺条件。     

菠萝汁对牛肉的嫩化效果研究

以菠萝汁和牛肉为原料,研究菠萝汁中菠萝蛋白酶对牛肉的嫩化作用,得到了嫩化的最佳工艺：菠萝汁浓度6%、时间60min、温度50℃、pH7.0。在此条件下,牛肉剪切力可降低50% 左右。对菠萝汁、生姜汁、木瓜蛋白酶嫩化产品与对照组进行了风味、色泽、剪切力的对比,结果表明：菠萝汁较生姜汁能够显著(p ≤ 0.05)提高产品的风味,相比木瓜蛋白酶及对照组其风味也有不同程度提高;菠萝汁、生姜汁、木瓜蛋白酶都能极显著(p ≤ 0.01)的提高产品的嫩度,而三种嫩化产品之间嫩度没有显著差异;用菠萝汁嫩化牛肉,在牛肉腌制后,其色度的b 值和a/b 值相对于对照组有极显著(p ≤ 0.01)提高,而在煮制后,只有b 值和对照组有显著(p ≤ 0.05)差异,而a/b 值无显著差异,表明用菠萝汁嫩化牛肉不会对产品的色泽造成不良影响。     

Effects of Blade Tenderization and Proteolytic Enzymes on Restructured Steaks from Beef Bullock Chucks

Three studies were conducted to determine the effects of blade tenderization (BT), fungal protease, ficin and papain on sensory ratings, textural properties and frozen storage life of restructured steaks from beef bullock chuck. Neither blade tenderizing of chuck muscles prior to incorporating it into restructured steaks nor the use of 0.05% or 0.10% fungal protease had an effect on the amount of connective tissue or textural properties of the cooked product. The addition of 0.10% fungal protease to restructured steaks increased the frozen storage life of the restructured steaks from 82 days (0%) to 149 days and over 157 days for 0.05%. The addition of ficin and papain had a detrimental effect on texture, flavor and overall satisfaction ratings. The methods tested in the present study are not suitable treatments for reducing the amount of detectable connective tissue in restructured steaks from beef bullock chucks.     

风味油炸鸡肉工艺优化及影响因素研究

研究了木瓜蛋白酶对油炸鸡肉制品嫩度的影响,对酶用量、温度和时间进行实验,通过L9（33）正交实验得到最佳工艺。结果显示：木瓜蛋白酶的用量、处理温度和时间对鸡肉的持水力、含水量、剪切力都有影响。木瓜蛋白酶嫩化的最佳条件是：酶用量0.01%、温度30℃、时间1.5h;因素的显著水平依次为：酶用量〉时间〉温度。在确定最佳工艺条件下,分别采用微波杀菌和高压杀菌两种不同方法,结果显示：采用温度为121℃,时间为20min高温高压杀菌技术,鸡肉的持水力为52%;而采用红外微波杀菌技术,设定温度为60℃,时间为5min,功率为640W[7],鸡肉的持水力为54.56%。     

响应面法优化木瓜蛋白酶-复合磷酸盐嫩化低档部位牛肉工艺

采用响应面回归设计来探究复合磷酸盐与木瓜蛋白酶复配使用嫩化低档部位烧烤牛肉的最佳条件。以单位肉中木瓜蛋白酶活力、复合磷酸盐质量浓度和作用时间为嫩化因子,以剪切力值和感官评价得分为响应值,运用Design-Expert 8.05软件对测得的结果建立二次回归模型。结果表明,复合磷酸盐与木瓜蛋白酶配合使用可以有效降低中低档部位牛肉的剪切力值,同时适当减少酶的用量,提高肉的保水性,得到更好的感官评价效果。最佳嫩化条件为：木瓜蛋白酶活力9.44 U/g、复合磷酸盐质量浓度18.35 mg/mL、作用时间9.09 h。在此条件下,低档部位烧烤牛肉的剪切力预测值为17.25 N,感官得分为5.02,整体感受较满意。经过实验验证,实测值与预测值吻合良好,说明响应面模型具有较好的预测能力,能有效用于剪切力值和感官评分的预测。     

Effect of Actinidin on the Protein Solubility, Water Holding Capacity, Texture, Electrophoretic Pattern of Beef, and on the Quality Attributes of a Sausage Product

ABSTRACT:  The objective of this study was to study the effect of actinidin, a sulfhydryl protease from kiwi fruit, on the protein solubility (nitrogen solubility index [NSI]), water holding capacity (WHC), texture, and SDS–PAGE pattern of beef and to evaluate the effect of pretreatment of beef with actinidin on the quality attributes of a sausage product. Actinidin was partially purified by precipitation with ammonium sulfate, followed by DEAE-Sephadex column chromatography. Actinidin significantly ( P < 0.05) increased NSI and WHC of beef; the highest NSI and WHC (approximately 20% and 8% increase, respectively) was observed when beef was incubated with 0.9 unit enzyme/g beef. Texture analysis indicated increased tenderization (10% decrease in shear force) when slices of cattle beef were treated with actinidin at 37 °C for 2 h. SDS–PAGE results indicated appearance of several low molecular weight bands (<10 kDa) after treating beef with different levels of actinidin for 30 or 60 min. Slight changes in protein band in the range of 100 to 120 kDa and 13 to 25 kDa were also observed. Use of actinidin-tenderized beef significantly improved emulsion stability, texture, and organoleptic properties of the sausage product.     

复合嫩化剂对猪肉嫩化效果的研究

首先通过单因素实验确定不同浓度的木瓜蛋白酶、氯化钠和氯化钙对猪肉嫩度的影响。再采用Box-Behnken设计和响应曲面中心组合设计法,建立复合嫩化剂对猪肉嫩度影响的响应模型,对木瓜蛋白酶浓度、氯化钠浓度和氯化钙浓度三因素及其两两交互作用进行分析与评价。实验结果表明:响应模型的拟合度高,试验误差小,通过实验数据分析发现木瓜蛋白酶、氯化钠和氯化钙都可增加猪肉脯的嫩度,其中氯化钙与木瓜蛋白酶对猪肉剪切力影响显著,而氯化钠的加入能显著降低猪肉的烹饪失水率,通过对剪切力拟合方程和烹饪失水率拟合方程的联合求解,优化出复合肉嫩化剂的配方组成为:氯化钠浓度6%、氯化钙浓度3.5%,木瓜蛋白酶120U/ml。在上述优化条件下,实际验证猪肉剪切力为2.10kg,烹饪失水率为34.5%。     

Effects of mechanical treatments and moisture enhancement on the processing characteristics and tenderness of beef semimembranosus roasts

The combined effect of blade tenderization (TD,NTD), pre-massaging (0 and 30min), moisture enhancement and post-injection tumbling (2h) on the chemical, binding and textural characteristics of pre-cooked roasts made from beef top round was investigated. Properties of the beef roasts were determined by measuring processing (i.e., cooking yield, expressible moisture (EM)) and textural characteristics (Warner-Bratzler shear, Kramer shear (KS), texture profile analysis). Brine injection helped to improve the cook yield and had the largest effect on tenderness of semimembranosus muscles. Post-injection tumbling did not significantly improve yield and textural properties of roasts; however, combined with the tenderization, it had beneficial effects on water holding and moisture retention. Pre-tumbling and blade tenderization treatments prior to injection generally were found to be beneficial for textural characteristics; pre-tumbling also tended to improve cook yield, but did not influence EM. However, no synergistic effect between these two variables was observed. An interaction between injection/tumbling and pre-tumbling was observed for KS. There was a significant improvement of KS values of roasts due to pre-tumbling observed for either non-injected roasts or those injected but without tumbling. However, no additional reduction in shear force was observed with pre-tumbling when roasts were tumbled after injection. This suggests that pre-tumbling may not be necessary to ensure more tender roasts when post-injection tumbling is applied, but would be beneficial for non-injected roasts or when tumbling is not applied after injection.