Research On Storage Stability Of Ghee

The ghee is a unique traditional dairy product in China because of the high nutritionalvalue and function. Ghee uses milk or goat milk as raw material, forms a unique aroma andtaste through special process of whipping and fermentation. The impact of storagetemperature, light, metal ions, casein, lactose and antioxidant on oxidation stability of gheewere studied in this paper, which providing theoretical basis for ghee industrial production.Based on a large number of references, we decided to use peroxide value, acid value,texture and sensory evaluation to evaluate quality change of ghee. At the same time, theelectronic noses were used to discriminate different ghee samples with PCA (principalcomponent analysis) method. An HS-SPME-GC-MS coupled with GC-MS method wasdeveloped and applied for the chang of flavor compounds in ghee.During250days of monitoring, it was found that temperature played an important roleon ghee storage stability. The results showed that the POV and AV of ghee storaged in25℃, which maximum were5.99meq/kg and4.43mg/g respectively, rised rapidly thanthose storaged in10℃and4℃. The odor material change could be slower and thegeneration of aldehyde material could ben weakened when ghee storaged in lowtemperature. With the increase of temperature, oxidation of ghee enhanced, at the sametime consistency and sensory evaluation decreased obviously. Ghee’s edibleness was lostafter storaged in25℃for210days. The order of storage stability was4℃＞10℃＞25℃.The results showed that the POV of ghee storaged in light, which maximum was149.22meq/kg, rised rapidly than that storaged in dark place. The influence of light onghee’s stability was more obvious than temperature in POV. Light could active oxygen,accelerate the process of automatic oxidation and rancidity, and make ghee’s smell change.The influence of light on texture was not as obvious as that of temperature. It was showedthe odor material changed, consistency increased and ghee had no edibleness after beingstoraged in light for100days. The shelf life of ghee could be extended significantly whenstoraged in dark place.Different mass concentration of copper, ferric ions, casein and lactose were added intoghee respectively, and then ghees were accelerated oxidation. The results showed thatcopper ion could accelerate the oxidation of ghee, and the oxidation was enhanced withthe increasing of mass concentration of copper ions.1ug/g ferric ions could delayoxidation of ghee, while5μg/g ferric ions and10μg/g ferric ions had the opposite effect,and10μg/g ferric ions promote oxidation ability was stronger than5μg/g ferric ions. Withthe increase of casein content, the oxidation starting point of ghee delayed in turn. Withthe lactose content increasing, peroxide value of ghee decreased in turn.The antioxidant effects of clove essential oil, clove basil essential oil, laurel essential oil, cinnamon essential oil, blue perilla oil and red perilla oil, vitamin E, and the syntheticantioxidant of BHT in ghee were studied in this paper. The results showed that theoptimum dosages of clove essential oil were0.08%. The antioxidantive of Clove essentialoil was superior to other essential oils and vitamin E. The antioxidation ability ofantioxidant used in this paper were0.020%BHT>0.08%clove essential oil>0.005%BHT>0.03%vitamin E.