Food Biotechnology Group, Section of Analytical Environmental and Applied Chemistry, Department of Chemistry, University of Patras, 26500, Patras, Greece.
Appl Biochem Biotechnol. 2010 Mar;160(6):1734-43. doi: 10.1007/s12010-009-8645-5. Epub 2009 May 17.
This paper concerns the effect of thermal-drying methodology on the investment cost for dried kefir cells production in order to be used as starter culture in cheese manufacturing. Kefir cells were produced at pilot plant scale using a 250-L bioreactor and whey as the main substrate. Kefir cells were subsequently dried in a thermal dryer at 38 degrees C and used as a starter culture in industrial-scale production of hard-type cheeses. The use of thermally dried kefir as starter culture accelerated ripening of cheeses by increasing both lipolysis and fermentation rate as indicated by the ethanol, lactic acid, and glycerol formation. Additionally, it reduced coliforms and enterobacteria as ripening proceeded. This constituted the basis of developing an economic study in which industrial-scale production of thermally dried kefir starter culture is discussed. The industrial design involved a three-step process using three bioreactors of 100, 3,000, and 30,000 L for a plant capacity of 300 kg of thermally dried kefir culture per day. The cost of investment was estimated at 238,000 euro, which is the 46% of the corresponding cost using freeze-drying methodology. Production cost was estimated at 4.9 euro/kg of kefir biomass for a 300-kg/day plant capacity, which is the same as with the corresponding cost of freeze-dried cells. However, the estimated added value is up to 10.8 x 10(9) euro within the European Union.
本文探讨了热干燥方法对干酸面团细胞生产投资成本的影响，以便将其用作奶酪制造中的起始培养物。使用 250-L 生物反应器和乳清作为主要基质，在中试工厂规模上生产酸面团细胞。然后，在 38°C 的热干燥器中干燥酸面团细胞，并将其用作工业规模生产硬奶酪的起始培养物。使用热干燥的酸面团作为起始培养物，通过提高脂解和发酵速度来加速奶酪的成熟，如乙醇、乳酸和甘油的形成所示。此外，随着成熟的进行，它还减少了大肠菌群和肠杆菌。这为开发经济研究奠定了基础，该研究讨论了工业规模生产热干燥酸面团起始培养物的问题。工业设计涉及一个三步过程，使用三个 100、3000 和 30000 L 的生物反应器，每天生产 300 公斤热干燥的酸面团培养物。投资成本估计为 238000 欧元，这是使用冷冻干燥方法的相应成本的 46%。对于 300 公斤/天的生产能力，生产成本估计为每公斤酸面团生物质 4.9 欧元，与冷冻干燥细胞的相应成本相同。然而，在欧盟范围内，估计的附加值高达 10.8 亿欧元。
