Article InformationAdvantages of freezing of dough are reduction of losses caused by aging of products. But freezing deteriorates the baking quality of frozen bread dough. These include gradual loss of the dough strength, reduced yeast activity and deterioration in the texture of the final product. The negative effects of freezing and defrosting of dough can be reduced by incorporating hydrocolloids in dough. Furthermore Biogenic ice nucleators, such as extracellular ice nucleators (ECINs) isolated from Erwinia herbicola, are a group of lipoglyco proteinsthat has been demonstrated to minimize the supercooling. Ice nucleation materials function as heterogeneous ice nucleators to minimize the supercooling of water. Mechanism of cryoprotective effects from extracellular ice nucleators was possibly that ECINs helped in preserving the viability of yeast cellsduring freeze/thaw cycles. At the end of this study we reviewed the ultrasound-assisted freezing; this method can improve the quality of frozen food without the need for additional additives.

The specific effects of chilling and freezing are meat tenderness and texture, drip production, meat colour and appearance and odor and flavor. Low temperatures are required during carcass storage to prevent microbial spoilage. Cold shortening or cold toughening depends on the difference between hot carcass and environmental temperatures. Carcass size and degree of fatness are other factors that influence carcass temperature decline.Most concern during storage, distribution and retail display of meat and meat products is the minimum growth temperature for a microorganism. Domestic refrigeration and freezing significantly improves the texture, juiciness and aroma of meat. This paper discusses the effects of chilling and freezing on the quality of meat.

Black plum peel is the by-product of plum processing and is a valuable source of antioxidants and phenolic compounds. In this research, total phenolic compounds, total flavonoid content and antioxidant activity of black plum peel were measured. After that, black plum peel extract (in concentrations 0, 400, 800, 1200 and 2000 ppm) as a natural antioxidant for improving the stability of soybean and sunflower oil was used. The oxidative stability parameters of oils (peroxide value, free fatty acids, thiobarbituric acid, conjugated dienes, and carbonyl value) were measured at 60 °C for 4–16 days. Antioxidant activity, total phenolic compounds and total flavonoid content of black plum peel were 86.87% and 100.53 mg GA /g and 871.062 mg Quercetin/g respectively. Black plum peel extract could have a significant positive effect (P<0.05) on improvement of the quality and stability parameters of soybean oil and sunflower oil. The oxidative stability parameters for commercial oils and samples containing black plum peel extract were near each other and in an acceptable range. So, black plum peel is recommended as an oxidative stabilizer of oils and alternative synthetic antioxidants.