تاثير اسانس‌هاي رازيانه و زنجبيل بر خواص حسي و ماندگاري شير گاو

Effect of Fennel and Ginger Essences on Sensory Characteristics and Shelf Life of Cow Milk

هدف اين مطالعه بررسي تأثير غلظت هاي مختلف (0، 100، 250 ، 500 و 1000 پي‌پي‌ام) اسانس‌هاي رازيانه و زنجبيل بر ويژگي‌هاي ميكروبي، حسي و مدت‌زمان نگهداري شير پاستوريزه شده در طول مدت نگهداري در يخچال بود. نتايج نشان داد كه بيشترين زمان نگهداري در تيمار زنجبيل 500 و 1000 پي پي ام (16 روز) و كمترين عمر نگهداري در تيمار شاهد (4 روز) مشاهده شد. نتايج مشخص كرد كه استفاده از غلظت‌هاي مختلف اسانس‌ها باعث كاهش شمارش كلي باكتري‌ها و كلي فرم‌ها نسبت به نمونه شاهد شد اما تأثيري بر ميزان باكتري‌هاي سرمادوست نداشت. تيمارهاي حاوي 100 و 250 پي پي ام اسانس زنجبيل بيشترين امتياز را از لحاظ طعم و مزه دريافت كردند. بيشترين امتيازات بو مربوط به سطوح 100، 250 و 500 پي پي ام اسانس زنجبيل بود. نمونه‌هاي حاوي 1000 پي پي ام اسانس رازيانه امتياز كمتري از لحاظ بو دريافت كردند. بطور كلي غلظت‌هاي كم اسانس زنجبيل هم به دليل پذيرش ويژگي‌هاي حسي از نظر مصرف‌كننده‌ها و هم به دليل كاهش رشد باكتري‌ها و افزايش مدت‌زمان نگهداري توصيه مي‌شوند.

Essential oils and herbal extracts from medicinal plants as a source of natural antioxidants, antimicrobial, anticancer and biologically active compounds have attracted a great deal of interesting applications in fresh and processed food preservation, pharmaceuticals, alternative medicine and natural-based therapies. In this study the effect of various concentrations (0, 100, 250, 500 and 1000 ppm) of fennel and ginger essence on microbial, chemical, sensory characteristics and shelf life of pasteurized milk during storage at refrigerator condition was studied. Results showed that here was the highest storage life in 500 and 1000 ppm ginger treatment (16 day) and the lowest storage life in control treatment (4 day). As the storage progressed a general decreasing trend in the pH content was observed. In various levels of ginger essence pH during storage time was increased. The results revealed that by use of various concentrations of essences, the total count and coliform bacteria was decreased but these essences had no effect on Psychrotrophic bacteria count. Sensory properties such as odor and flavour were affected by various concentrations of essences. Samples with 100 and 250 ppm ginger essence treatments had higher flavour and taste scores than others. The highest odor scores were related to 100, 250 and 500 ppm ginger essence. Samples with 1000 ppm fennel essence had the lowest odor score. In general, low concentrations of ginger essence due to acceptance of the organoleptic characteristics from the consumer view as well as reduce microbial growth and increase storage time was recommended.