LASEFI/DEA/FEA (School of Food Engineering)/UNICAMP (University of Campinas), Rua Monteiro Lobato, 80, Campinas, SP CEP:13083-862, Brazil.
LASEFI/DEA/FEA (School of Food Engineering)/UNICAMP (University of Campinas), Rua Monteiro Lobato, 80, Campinas, SP CEP:13083-862, Brazil.
Ultrason Sonochem. 2020 Sep;66:105068. doi: 10.1016/j.ultsonch.2020.105068. Epub 2020 Mar 16.
This study presents the production of a novel natural blue colorant obtained from the cross-linking between milk proteins and genipin assisted by low-frequency and high-power ultrasound technology. Genipin was extracted from unripe Genipa americana L. using milk as a solvent. Also, milk colloidal system was used as a reaction medium and carrier for the blue color compounds. The effects of ultrasound nominal power (100, 200, 300, and 400 W) on the blue color formation kinetics in milk samples were evaluated at 2, 24, and 48 h of cold storage in relation to their free-genipin content and color parameters. In addition, Fourier transform infrared (FTIR) spectrum, droplet size distribution, microstructure, and kinetic stability of the blue colorant-loaded milk samples were assessed. Our results have demonstrated that the ultrasound technology was a promising and efficient technique to obtain blue colorant-loaded milk samples. One-step acoustic cavitation assisted the genipin extraction and its diffusion into the milk colloidal system favoring its cross-linking with milk proteins. Ultrasound process intensification by increasing the nominal power promoted higher genipin recovery resulting in bluer milk samples. However, the application of high temperatures associated with intensified acoustic cavitation processing favored the occurrence of non-enzymatic browning due to the formation of complex melanin substances from the Maillard reaction. Also, the blue milk samples were chemically stable since their functional groups were not modified after ultrasound processing. Likewise, all blue colorant-loaded milk samples were kinetically stable during their cold storage. Therefore, a novel natural blue colorant with high-potential application in food products like ice creams, dairy beverages, bakery products, and candies was produced.
本研究提出了一种新型天然蓝色着色剂的生产方法，该着色剂是通过低频和高功率超声技术辅助乳蛋白与京尼平交联得到的。京尼平是从未成熟的美洲蒲桃（Genipa americana L.）中用牛奶提取的，牛奶胶体体系被用作蓝色化合物的反应介质和载体。研究了超声标称功率（100、200、300 和 400 W）对牛奶样品中蓝色形成动力学的影响，在 2、24 和 48 小时冷藏条件下，评估了其游离京尼平含量和颜色参数。此外，还评估了负载蓝色着色剂的牛奶样品的傅里叶变换红外（FTIR）光谱、液滴尺寸分布、微观结构和动力学稳定性。结果表明，超声技术是一种很有前途和有效的技术，可以获得负载蓝色着色剂的牛奶样品。一步声空化辅助京尼平提取并扩散到牛奶胶体体系中，有利于其与乳蛋白交联。通过增加标称功率来强化超声过程可以促进更高的京尼平回收，从而使牛奶样品呈现更蓝的颜色。然而，由于美拉德反应形成复杂的黑色素物质，与强化声空化处理相关的高温应用促进了非酶褐变的发生。此外，由于超声处理后其功能基团没有被修饰，因此蓝色牛奶样品在化学上是稳定的。同样，所有负载蓝色着色剂的牛奶样品在冷藏期间的动力学稳定性都很好。因此，生产出了一种具有高应用潜力的新型天然蓝色着色剂，可应用于冰淇淋、乳制品饮料、烘焙产品和糖果等食品。
