بررسی اثرات فرمولاسیون، نوع پوشش و شرایط بسته‌بندی برمیزان آب‌اندازی ژامبون گوشت و مرغ طی دوره نگهداری

انواع سوسیس و کالباس در بسته‌بندی‌های تحت خلاء از جمله فرآورده‌های گوشتی هستند که به‌دلیل تنوع، راحتی در مصرف و اقتصادی بودن رایج می‌باشند. مهمترین مشکل عمده تولید، نگهداری و فروش این نوع فراورده‌های گوشتی، آب‌اندازی (سینرسیس) آنها درون بسته‌بندی تحت خلاء است. آب‌اندازی بسته علاوه بر ظاهر ناپسند، منجر به تسریع رشد و تکثیر میکروبی و تغییرات نامطلوب در عطر و طعم محصول می‌گردد. در این پژوهش عوامل مختلفی از جمله اثر سطوح مختلف کیتوزان و نشاسته اصلاح شده سیب‌زمینی در فرمولاسیون، بر روی میزان آب‌اندازی، ph، جمعیت میکروبی و ارزیابی حسی در دو نوع محصول ژامبون گوشت گاو و ژامبون گوشت مرغ در طول مدت زمان نگهداری مورد بررسی قرار گرفت. در ادامه اثر روش بسته‌بندی تحت خلاء و میزان خلاء ایجاد شده در بسته بر روی میزان آب‌اندازی بررسی گردید. نتایج نشان داد افزودن کیتوزان و نشاسته اصلاح شده سیب‌زمینی به‌طور معنی‌داری باعث کاهش آب‌اندازی محصول در طول مدت نگهداری می‌شوند در حالی که در تمامی نمونه‌ها با افزایش مدت زمان نگهداری میزان آب‌اندازی افزایش یافت (p<0/05). کیتوزان به‌دلیل اثرات ضدمیکروبی باعث کاهش جمعیت میکروبی و مانع کاهش ph گردید. طبق نتایج ارزیابی حسی در طول مدت زمان نگهداری کیفیت حسی نمونه‌ها به‌طور معنی‌داری دچار افت گردید در حالی که کیتوزان اثرات مثبت معنی داری بر روی پارامترهای حسی در طول مدت زمان نگهداری داشت(p<0/05). همچنین نتایج نشان داد که آب‌اندازی ژامبون‌ها تحت تاثیر نوع بسته‌بندی و میزان خلاء نیز قرار دارد به‌گونه‌ای که بسته‌بندی skin نسبت به بسته‌بندی‌های تحت خلاء ساده میزان آب‌اندازی کمتری از خود نشان دادند و با افزایش میزان خلاء بسته‌بندی، میزان آب‌اندازی افزایش معنی‌داری داشت (p<0/05). نتایج نشان داد نشاسته سیب‌زمینی 5% و کیتوزان 0/6% و بسته‌بندی skin در میزان خلاء 30 میلی‌بار باعث کاهش آب‌اندازی از 1/7 به 1/3 گردید. در مجموع می‌توان نتیجه گرفت که با افزوده نشاسته اصلاح شده سیب‌زمینی و کیتوزان به فرمولاسیون و همچنین استفاده از بسته‌بندی skin با میزان خلاء کمتر می‌توان میزان آب‌اندازی فراورده‌های گوشتی را به میزان قابل توجهی کاهش داد.

Investigation the effect of formulation and condition of packaging on the Ham syneresis during Shelf Life

Introduction: Meat and meat products are important sources of protein, fat, essential amino acids, minerals and vitamins, and other nutrients. Bologna sausage, a cooked meat product, is one of the most accepted processed meat products and is consumed and enjoyed worldwide. Among the meat products, sausage and bologna in vacuum packages due to their variety, easy to use applications and being economical, have become commonplace. The most important problem with the production, storage, and sale of this kind of meat products is their syneresis in the vacuum packages. In addition to an unpleasant appearance, syneresis leads to accelerating microbial growth and undesirable changes in the flavor and odor of the product.;The addition of functional ingredients helps to modify the overall technological and sensorial characteristics of a meat system such as water holding capacity (WHC), fat holding capacity, and texture properties and decrease the syneresis. Syneresis and purge are seen as a result of retrogradation of starch and this is very common in sliced and vacuumpacked meat products. Storage of meat products containing highamylose starches, at low temperatures from around –1 °C to 0 °C for a prolonged time also favors retrogradation. The level of retrogradation depends on the type of starch and wheat starch demonstrating the greatest tendency towards retrogradation. Chitosan is a natural cationic polysaccharide antibacterial activity and antioxidant properties in muscle foods during storage. The aim of this study was Investigation the addition of functional ingredients such as chitosan and potato modified starch in the formulation on the amount of syneresis, pH, total microbial count and sensory evaluation in two type of products including beef ham and chicken ham were examined during storage. Then, the effect of vacuum packaging type and the amount of vacuum created in the package on the amount of syneresis were investigated.; ;Material and methods: In this study, first various factors such as three levels of chitosan (0, 0.3 and 0.6%) and replace the wheat starch with three levels of potato modified (0, 5 and 10%) in the formulation on the amount of syneresis, pH, total microbial count and sensory evaluation in two type of products including beef ham and chicken ham were examined during storage time (1, 15 and 30 days). In this part of the study, samples with the least syneresis were selected. After that various factors of packaging such as two types of vacuum packaging(simple vacuum pack and skin pack) and the amount of vacuum(5 and 30 millibars) created in the package on the amount of syneresis were examined during storage(1, 15 and 30 days). Wheat starch, potato starch, and chitosan were purchased, respectively, from Faradane Company, KMC Company, and Sinaseven Company. The chicken meat was purchased from Fileh Amol Company. The beef was purchased from the Minerva Company of Brazil. All steps of samples’ preparation were performed in the Kalleh Amol Meat company. The chicken ham samples in this study consisted of 90% of the chicken meat and beef ham samples consisted of 90% of beef. Vacuum packaging was done using the machines which were manufactured by the German company Multivac. Syneresis was measured using the method suggested by Cesare et al. (e 2013). The initial weight of the ham slices before vacuumpacked was measured (P1); on the day of the analysis, the packaging was opened and the slices were dried with a disposable absorbent towel, then the dried ham slices were weighed again (P2). Syneresis was expressed as Syneresis= (P1 P2) ×100/P1. This study was conducted in a completely randomized design and Duncan multiranged test was used to determine differences between samples at 95% confidence level.; ;Results and discussion: According to the results of analysis of variance, there was no significant difference between the syneresis of beef and chicken ham. The effect of storage time was significant on the syneresis and the syneresis rate increased with increasing storage time. Also, the results showed that adding chitosan and potato modified starch significantly (p lt;0.05) reduced the product apos;s syneresis during storage. Potato starch has more water storage capacity and more amylopectin than wheat starch. For this reason, potato starch has a weaker retrogradation and less syneresis. Chitosan is a cationic polysaccharide with waterabsorbing polar groups. Chitosan also was prevented from decreasing the product’s pH during storage time, that this result showed the antimicrobial effect of chitosan on acid lactic bacteria, especially in 15 and 30 days of storage. For that reason, chitosan prevents product’s pH to reach to its isoelectric pH. According to the sensory evaluation results, during the maintenance period, the sensory quality decreased significantly while chitosan had a significant positive effect on sensory parameters during storage time (P lt;0.05). The type of vacuum packaging and the amount of vacuum created in the package showed a significant effect on the amount of samples’ syneresis. Skin packaging showed less syneresis rates than simple vacuum packages. This result can be due to two reasons: one is the shrinkage of the product in the package, and the other is the amount of the film packing tangency on the surface of the products. So that by increasing the amount of vacuum, syneresis value increased significantly. Increasing the negative pressure inside the package caused increase the mechanical pressure by the packaging film on the product. In total, it can be concluded that with the addition of modified potato starch and chitosan to the formulation, as well as the use of lowervacuum Skin packaging, the amount of syneresis of meat products can be significantly reduced.