Sakkas Lambros, Karela Marianna, Zoidou Evangelia, Moatsou Golfo, Moschopoulou Ekaterini
Laboratory of Dairy Research, Department of Food Science and Human Nutrition, Agricultural University of Athens, Iera Odos 75, 118 55 Athens, Greece.
Foods. 2023 Oct 21;12(20):3860. doi: 10.3390/foods12203860.
Yogurt acid whey (YAW), a by-product of strained yogurt production, is a strong environmental pollutant because of its high organic load. Hence, efforts are made for its utilization to minimize its disposal in the environment. This study deals with the incorporation of YAW in yogurt ice cream (YIC) by partial replacement of yogurt with simultaneous lactose hydrolysis (LH) of the formulated YIC mix. Six YIC mix formulations were made, two without YAW (non-LH- and LH-control samples, A and AH), two with 12.5% YAW (samples B and BH), and two with 18.75% YAW (samples C and CH). The results showed that the partial replacement of yogurt with YAW decreased significantly ( < 0.05) the total solids of B, BH, C, and CH products (31.72 ± 0.14%, 31.92 ± 0.21%, 30.94 ± 0.14%, and 31.27 ± 0.10%, respectively) compared to the total solids of control products A and AH (33.30 ± 0.36% and 33.74 ± 0.06%, respectively). In contrast, the overruns increased (51.50 ± 2.36%, 58.26 ± 0.09%, 56.86 ± 1.92%, and 65.52 ± 1.30% for the B, BH, C, and CH products, respectively) compared to control samples (42.02 ± 2.62% and 49.53 ± 2.12% for A and AH, respectively). LH significantly decreased the freezing point and the viscosity of the YIC mixes but increased the overruns of the products as shown previously. YAW significantly decreased the hardness of the B and C products (56.30 ± 2.11 N and 43.43 ± 3.91 N, respectively) compared to control A (81.14 ± 9.34 N), and LH decreased it even more, leading to a rather soft scoop YIC. AH, BH, and CH YICs exhibited better melting properties despite the lack of fat destabilization in all samples. After 60 days of storage, counts of yogurt starter microorganisms were still >10 cfu/g and DPPH radical scavenging activity had increased in all products. In the sensory evaluation test, lactose-hydrolyzed samples AH, BH, and CH had less intense sandiness and, as expected, more intense sweetness. In conclusion, in the framework of the circular economy, it is possible for the YAW to be used as a resource material at a ratio of 12.5% to produce a YIC product without leaving behind any new waste.
酸奶酸乳清（YAW）是过滤型酸奶生产的副产品，因其高有机负荷而成为一种严重的环境污染物。因此，人们致力于对其加以利用，以尽量减少其在环境中的排放。本研究通过部分替代酸奶并同时对配制的酸奶冰淇淋（YIC）混合料进行乳糖水解（LH），将YAW掺入酸奶冰淇淋中。制备了六种YIC混合料配方，两种不含YAW（非LH对照样品和LH对照样品，分别为A和AH），两种含12.5%YAW（样品B和BH），两种含18.75%YAW（样品C和CH）。结果表明，与对照产品A和AH的总固形物含量（分别为33.30±0.36%和33.74±0.06%）相比，用YAW部分替代酸奶显著降低了（<0.05）B、BH、C和CH产品的总固形物含量（分别为31.72±0.14%、31.92±0.21%、30.94±0.14%和31.27±0.10%）。相比之下，膨胀率增加了（B、BH、C和CH产品的膨胀率分别为51.50±2.36%、58.26±0.09%、56.86±1.92%和65.52±1.30%），而对照样品的膨胀率分别为42.02±2.62%和49.53±2.12%。如前所示，乳糖水解显著降低了YIC混合料的冰点和粘度，但增加了产品的膨胀率。与对照A（81.14±9.34N）相比，YAW显著降低了B和C产品的硬度（分别为56.30±2.11N和43.43±3.91N），而乳糖水解进一步降低了硬度，导致YIC的勺挖性相当软。尽管所有样品中均不存在脂肪失稳现象，但AH、BH和CH型YIC具有更好的融化特性。储存60天后，酸奶发酵剂微生物的数量仍>10 cfu/g，且所有产品中的DPPH自由基清除活性均有所提高。在感官评价测试中，乳糖水解样品AH、BH和CH的砂质感较弱，且正如预期的那样，甜度更强。总之，在循环经济的框架下，YAW有可能以12.5%的比例用作原料来生产YIC产品，且不会产生任何新的废弃物。
