Effect of quality of milk on physico-chemical characteristics of buffalo milk concentrate (khoa) during storage

Khoa and khoa based traditional dairy products: preparation, spoilage and shelf life extension

Khoa and khoa based products (burfi, peda, kalakand, milk cake, etc.) are a category of traditional dairy products of Indian subcontinent. They are prepared by open pan desiccation along with stirring and scraping of milk to the desired consistency, followed by addition of sugar and / or colour and flavoring ingredients. The peculiar sensory attributes developed during their course of preparation makes them unique, but their short shelf-life is a major challenge faced by the dairy industries. They are spoiled mainly because of yeast and mold growth along with detrimental changes in the sensory attributes. This review describes various preservation techniques explored in the last two decades such as packaging interventions, modified atmospheric and active packaging, chemical preservation, water activity modification, natural preservation, thermal treatments, bio-preservation, etc. which can be used either singly or in combination (hurdle technology), to enhance the shelf life of these milk products.

Effect of adding Aloe vera jell on the quality and sensory properties of yogurt

This study was planned to investigate the effect of replacing milk fat with aloe vera gel addition on yogurt quality. Purposely, yogurt was prepared with different concentration of aloe vera gel and coded as AGY0, = Control (3.5% fat and no AG), AGY1 = (1% fat and 1% AG), AGY2 = (1% fat and 2% AG), AGY3 = (1% fat and 3% AG), AGY4 = (2% fat and 1% AG), AGY5 = (2% fat and 2% AG), and AGY6 = (2% fat and 3% AG). Aloe vera gel yogurt was analyzed for physicochemical, microbial, and sensory characteristics with defined interval (0, 7th, 14th, and 21st) days. All attributes of the yogurt were significantly (0.05) affected by the addition of aloe vera gel. Results showed that the pH (4.6-4.05), viscosity (46.4-4.3), WHC (32.8%-26.1%), fat (0.9%-3.48%), protein (3.14%-3.36%), lactose (4.07%-4.23%), ash (0.48%-0.63%), total solids (11.08%-17.18%), SNF (7.69-l5.21%), and TPC (2.36 × 107 to 1.02 × 107 CFU/ml) values of yogurt samples decreased with storage time. However, acidity and syneresis of yogurt increased with the passage of time ranging from 1.12%-1.67% and 0.9-5 ml, respectively. In conclusion, aloe vera improved the texture of the yogurt which leads to higher consumer acceptability. Addition of 3% aloe vera to 1% fat (AGY3) containing buffalo milk yogurt was found to best for physicochemical as well as organoleptic characteristics as well as organoleptic characteristics.

Characterization and Comparative Evaluation of Milk Protein Variants from Pakistani Dairy Breeds

The aim of study was to scrutinize the physicochemical and protein profile of milk obtained from local Pakistani breeds of milch animals such as Nilli-Ravi buffalo, Sahiwal cow, Kajli sheep, Beetal goat and Brela camel. Physicochemical analysis unveiled maximum number of total solids and protein found in sheep and minimum in camel. Buffalo milk contains the highest level of fat (7.45%) while camel milk contains minimum (1.94%). Ash was found maximum in buffalo (0.81%) and sheep (0.80%) while minimum in cow's milk (0.71%). Casein and whey proteins were separated by subjecting milk to isoelectric pH and then analyzed through sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE). The results showed heterogeneity among these species. Different fractions including α_S1, α_S2, κ-casein, β-casein and β-lactoglobulen (β-Lg) were identified and quantitatively compared in all milk samples. Additionally, this electrophoretic method after examining the number and strength of different protein bands (α_S1, α_S2, β-CN, α-LAC, BSA, and β-Lg, etc.), was helpful to understand the properties of milk for different processing purposes and could be successfully applied in dairy industry. Results revealed that camel milk was best suitable for producing allergen free milk protein products. Furthermore, based on the variability of milk proteins, it is suggested to clarify the phylogenetic relationships between different cattle breeds and to gather the necessary data to preserve the genetic fund and biodiversity of the local breeds. Thus, the study of milk protein from different breed and species has a wide range of scope in producing diverse protein based dairy products like cheese.

Physico-chemical properties of Khoa prepared from lactose hydrolyzed buffalo milk

Lactose is a reducing sugar which is abundantly found in mammalian milk. Lactose intolerance affects more than 70% of the world population, being apparent by the absence of β-galactosidase enzyme, thus leading to the inability to consume dairy products. In the present work, Khoa was prepared from lactose hydrolysed milk and its physico-chemical, textural and microbiological quality were examined during storage at 5-7 °C for 28 days. The sensory quality of low lactose Khoa was comparable with that of the control Khoa up to the 14th day of storage. Significant differences (p < 0.05) between the acidity, hydroxyl methyl furfural (HMF) content, lightness, redness, springiness, chewiness and hardness values of the low lactose Khoa and the control Khoa were observed. The standard plate count (SPC), coliform and yeast and mould counts of the low lactose Khoa were within Food safety and standards authority of India (FSSAI) standards throughout the 28 days of storage. Therefore, the low lactose Khoa developed in this study had different physicochemical properties from the control sample with better shelf life.