Northeast Dairy Foods Research Center, Department of Food Science, Cornell University, Ithaca, NY 14853.
University of Warmia and Mazury, Olsztyn, Poland 10-719.
J Dairy Sci. 2013 Apr;96(4):2035-2047. doi: 10.3168/jds.2012-6009. Epub 2013 Feb 15.
The goals of this study were to determine if adding annatto color to milk or applying a bleaching process to whey or microfiltration (MF) permeate influenced ultrafiltration (UF) flux, diafiltration (DF) flux, or membrane fouling during production of 80% whey protein concentrate (WPC80) or 80% serum protein concentrate (SPC80). Separated Cheddar cheese whey (18 vats using 900 kg of whole milk each) and MF permeate of skim milk (18 processing runs using 800 kg of skim milk each) were produced to make WPC80 and SPC80, respectively. The 6 treatments, replicated 3 times each, that constituted the 18 processing runs within either whey or MF permeate UF were as follows: (1) no annatto; (2) no annatto+benzoyl peroxide (BPO); (3) no annatto+hydrogen peroxide (H2O2); (4) annatto; (5) annatto+BPO; and (6) annatto+H2O2. Approximately 700 kg of whey or 530 kg of MF permeate from each treatment were heated to 50°C and processed in 2 stages (UF and DF) with the UF system in batch recirculation mode using a polyethersulfone spiral-wound UF membrane with a molecular weight cutoff of 10,000 Da. Addition of annatto color had no effect on UF or DF flux. The processes of bleaching whey or MF permeate with or without added color improved flux during processing. Bleaching with H2O2 usually produced higher flux than bleaching with BPO. Bleaching with BPO increased WPC80 flux to a greater extent than it did SPC80 flux. Though no differences in mean flux were observed for a common bleaching treatment between the WPC80 and SPC80 production processes during the UF stage, mean flux during WPC80 DF was higher than mean flux during SPC80 DF for each bleaching treatment. Water flux values before and after processing were used to calculate a fouling coefficient that demonstrated differences in fouling which were consistent with flux differences among treatments. In both processes, bleaching with H2O2 led to the largest reduction in fouling. No effect of annatto on fouling was observed. The reasons for flux enhancement associated with bleaching treatments are unclear.
本研究的目的是确定在生产 80%乳清蛋白浓缩物（WPC80）或 80%血清蛋白浓缩物（SPC80）时，向牛奶中添加胭脂树橙色素或对乳清或微滤（MF）渗透物进行漂白处理，是否会影响超滤（UF）通量、渗滤（DF）通量或膜污染。分别使用 900 公斤全脂牛奶生产 18 个切达干酪乳（使用 18 个罐）和 MF 渗透物（使用 800 公斤脱脂牛奶进行 18 次处理），以生产 WPC80 和 SPC80。在乳清或 MF 渗透物 UF 中进行的 18 次处理中的 6 个处理，每个处理重复 3 次，组成如下：（1）无胭脂树橙；（2）无胭脂树橙+过氧化苯甲酰（BPO）；（3）无胭脂树橙+过氧化氢（H2O2）；（4）胭脂树橙；（5）胭脂树橙+BPO；和（6）胭脂树橙+H2O2。大约 700 公斤乳清或每个处理的 530 公斤 MF 渗透物被加热至 50°C，并在 UF 系统中以分批循环模式在 2 个阶段（UF 和 DF）进行处理，使用截留分子量为 10000Da 的聚醚砜螺旋缠绕 UF 膜。添加胭脂树橙色素对 UF 或 DF 通量没有影响。用或不用添加的色素对乳清或 MF 渗透物进行漂白的过程改善了加工过程中的通量。用 H2O2 漂白通常比用 BPO 漂白产生更高的通量。用 BPO 漂白对 WPC80 通量的提高程度大于对 SPC80 通量的提高程度。虽然在 UF 阶段，WPC80 和 SPC80 生产过程中对常见的漂白处理没有观察到平均通量的差异，但对于每个漂白处理，WPC80 DF 的平均通量均高于 SPC80 DF 的平均通量。在处理前后使用水通量值计算污染系数，该系数表明处理之间的污染差异与处理之间的通量差异一致。在这两个过程中，用 H2O2 漂白导致污染的减少最大。没有观察到胭脂树橙对污染的影响。与漂白处理相关的通量增强的原因尚不清楚。
