Nicosia Fabrizio Domenico, Puglisi Ivana, Pino Alessandra, Baglieri Andrea, La Cava Rosita, Caggia Cinzia, Fernandes de Carvalho Antonio, Randazzo Cinzia Lucia
Department of Agricultural, Food and Environment, University of Catania, 95123 Catania, Italy.
ProBioEtna SRL, Spin off of University of Catania, Via Santa Sofia, 100, 95123 Catania, Italy.
Foods. 2022 Jul 28;11(15):2255. doi: 10.3390/foods11152255.
In the present study, a kiwifruit aqueous extract was developed and used as a coagulant enzyme in cheesemaking. In detail, polyacrylamide gel electrophoresis (SDS-PAGE) was used to investigate the presence of actinidin, the kiwifruit enzyme involved in κ-casein hydrolysis, in different tissues (pulp, peel, and whole fruit) of ripe and unripe kiwifruits. Data revealed the presence of the enzyme both in the peel and in the pulp of the fruit. Although the aqueous extract obtained from the kiwifruit peel was able to hydrolyze semi-skimmed milk, it did not break down κ-casein. The aqueous extract obtained from the pulp showed a hydrolytic activity toward both κ-casein and semi-skimmed milk. The values for milk-clotting and proteolytic activity of the kiwifruit pulp extract were evaluated at different temperatures and pH parameters in order to obtain a high value of the MCA/PA ratio; we found that a temperature of 40 °C in combination with a pH value of 5.5 allowed us to obtain the best performance. In addition, the data revealed a higher hydrolytic activity of the enzymatic preparation from ripe kiwifruits than that from unripe ones, suggesting the use of the extract from pulp of ripe kiwifruits in the laboratory-scale cheesemaking. The data showed that 3% (/) of the ripe kiwifruit pulp extract determined a curd yield of 20.27%, comparable to chymosin yield. In conclusion, the extraction procedure for kiwifruit aqueous extract proposed in the present study was shown to be a fast, cheap, chemical-free, and ecofriendly technology as a plant coagulant for cheese manufacturing.
在本研究中，开发了一种猕猴桃水提取物，并将其用作奶酪制作中的凝乳酶。具体而言，采用聚丙烯酰胺凝胶电泳（SDS-PAGE）研究了成熟和未成熟猕猴桃不同组织（果肉、果皮和整个果实）中参与κ-酪蛋白水解的猕猴桃酶——肌动蛋白酶的存在情况。数据显示该酶在果实的果皮和果肉中均有存在。尽管从猕猴桃果皮中获得的水提取物能够水解半脱脂牛奶，但它不能分解κ-酪蛋白。从果肉中获得的水提取物对κ-酪蛋白和半脱脂牛奶均表现出水解活性。为了获得较高的MCA/PA比值，在不同温度和pH参数下评估了猕猴桃果肉提取物的凝乳和蛋白水解活性；我们发现40℃的温度与5.5的pH值相结合能使我们获得最佳性能。此外，数据显示成熟猕猴桃的酶制剂水解活性高于未成熟猕猴桃，这表明在实验室规模的奶酪制作中可使用成熟猕猴桃果肉的提取物。数据表明，3%（/）的成熟猕猴桃果肉提取物可产生20.27%的凝乳产量，与凝乳酶的产量相当。总之，本研究中提出的猕猴桃水提取物提取方法被证明是一种快速、廉价、无化学物质且环保的技术，可作为奶酪制造的植物凝乳剂。
