การประยุกต์ใช้แนวทางตามพระราชดำริเกี่ยวกับเศรษฐกิจพอเพียงเพื่อการแก้ไขปัญหาน้ำนมดิบล้นตลาดในช่วงฤดูร้อนของเกษตรกรผู้เลี้ยงโคนม และสหกรณ์ผู้เลี้ยงโคนม ในภาคเหนือตอนบน

บทคัดย่อ

This research was dedicated to investigate different dairy products that could be manufactured by small and medium scale enterprises. The studied dairy products included salt coagulated cheese or sheeted milk, acid coagulated cheese or Paneer, whipped yoghurt and fiber-added dairy ice cream. In the work of salt coagulated cheese, several factors that affecting the production of the cheese, which were types of stabiliser, addition levels of stabiliser and pressing periods, and the shelf life of the cheese in brine solutions at different storage temperatures were examined. It was found that the salt concentration of salt coagulated cheese was increased at higher concentration levels of calcium chloride, but it was not in the presence of different concentration levels of calcium propionate. Cheese coagulated by calcium chloride had higher hardness values than those produced from calcium propionate, particularly at lower concentration levels of salt solution. Applying longer pressing periods produced salt coagulated cheeses with lower moisture contents, pH values and salt concentrations together with higher hardness values. Keeping quality of salt coagulated cheeses could be extended at refrigerated temperature, particularly when the cheese was stored in brine solutions. Salt coagulated cheese could be added in several food dishes, such as fried eggs or rice, noodles, bakery products and snacks. By the presence of the cheese in these products, the perception for the nutritional value of the food products would be significantly improved. Factors, such as types of acidulant, addition levels of acidulant, pressing and soaking periods, together with the keeping quality of acid coagulated cheese at refrigerated temperature w were scrutinised in this research project. The ash content of acid coagulated cheeses was reduced at higher addition level of acidulant, particularly for lime juice and 5% (w/v) citric acid. Higher addition levels of acid coagulant also caused lower pH and higher total acidities of the acid coagulated cheeses. Lower total microbial content was observed in the cheese coagulated with 10% acetic acid compared to those of the cheeses produced by lime juice and 5% citric acid. The yield, moisture content and intensity of red colour of acid coagulated cheeses were increased with longer t soaking period in chilled water. Acid coagulated cheeses packed in vacuum packaging significantly had lower pH, total acidity and total microbial number compared to those stored in plastic bags during 12 weeks of storage at chilled temperature. The production of whipped or aerated yoghurt was carried out by incorporating air in the yoghurt after the fermentation process. To understand this dairy product, important processing parameters, including processing equipment to incorporate the air, sugar, stabiliser and emulsifier, in conjunction with the shelf life of the product at 4C were investigated in the present work. Addition of air in yoghurt could be performed using a kitchen aid for a small and batch production of whipped yoghurt. The presence of 2% (w/v) sugar could significantly reduce the foam collapse in the whipped yoghurt after 24 h of the production process. Supplementation of xanthan gum produced stable foam that was not collapsed after 24 h of the production process and retarded whey drainage at addition levels of more than 0.6%. Three types of emulsifiers, including Distilled Monoglyceride type P(V), Plusco EA-100 and EC- 25K, did not assist in producing better physical and chemical properties of whipped yoghurt. During 3 weeks storage at refrigerated temperature, the overrun and conductivity of the whipped yoghurt were significantly increased. Optimum ingredients in the whipped yoghurt, which were 2% sugar and 0.6% xanthan gum, caused a small amou unt of the foam collapsed, less than 5%, within 21 days of storage at low temperature. The production and storage of whipped yoghurt did not significantly affect the number of Streptococcus thermophilus, whereas a reduction in the count of Lactobacillus bulgaricus was found after 2 weeks of storage at chilled temperature. Production of dietary fiber powders from orange, pineapple and carrot showed that the fiber powder from orange significantly had higher lightness (L* value), water activity, pH and oil holding capacity and lower dispersibility and yellow colour intensity compared to those of the powders extracted from pineapple and carrot. Higher addition levels of dietary fiber in ice creams tended to reduce the melting rate the corresponding ice cream. The flow behaviour of the fiber-added ice creams indicated a non-Newtonian fluid with high elastic modulus and low loss tangent. The supplementation of 1.5% dietary fiber powder from pineapple in the dairy ice cream did not significantly reduce the overall acceptance of the ice cream compared to the control ice cream (no addition of dietary fiber).

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