Boyacı Derya, Kavur Pelin Barış, Gulec Sukru, Yemenicioğlu Ahmet
Department of Food Engineering, Izmir Institute of Technology, 35430 Gulbahce Koyu, Urla, Izmir, Turkey.
School of Engineering, University of Lincoln, LN6 7TS Brayford Pool, Lincoln, United Kingdom.
Food Technol Biotechnol. 2021 Sep;59(3):337-348. doi: 10.17113/ftb.59.03.21.7029.
The use of gel-based systems as a novel method for the delivery of natural antimicrobial, antioxidant and bioactive compounds is a developing innovative solution for the food industry. This research aims to develop multifunctional active edible gels based on gelatine and its composites with improved mechanical properties.
Antilisterial and bioactive composite gels showing different physical and active properties from classical gelatine gel were developed by loading lysozyme and green tea extract into gelatine/starch and gelatine/wax composite gels. Mechanical properties, swelling profiles, colour, release profiles, and antimicrobial and bioactive properties of the gels were characterised.
Gelatine/wax gels showed 1.3- to 2.1-fold higher firmness and cutting strength than gelatine and gelatine/starch composite gels that had similar firmness and cutting strengths. Work to shear of both composite gels was 1.4- to 1.9-fold higher than that of gelatine gel. The gelatine/starch gel showed the highest water absorption capacity. Green tea extract reduced soluble lysozyme in all gels, but composite gels contained higher amount of soluble lysozyme than gelatine gel. All the gels with lysozyme inhibited growth in the broth media, while green tea extract showed antilisterial activity only in gelatine/wax gels. Gels with green tea extract showed antioxidant, antidiabetic (α-glucosidase and α-amylase inhibition), antihypertensive (angiotensin-converting enzyme inhibition) and antiproliferative activities (on Caco-2 human colon carcinoma cells). However, gelatine and gelatine/wax gels showed the highest antioxidant and antidiabetic activity. The gelatine/wax gels prevented phenolic browning, while green tea extract in other gels showed moderate or extensive browning.
This work clearly showed the possibility of improving mechanical properties and modifying water absorption and controlled release profiles of gelatine gels using gelatine/starch and gelatine/wax composites. The novel composite gels reduced browning of incorporated polyphenols and showed antilisterial and bioactive properties.
使用基于凝胶的系统作为一种新型方法来递送天然抗菌、抗氧化和生物活性化合物，是食品工业中一种不断发展的创新解决方案。本研究旨在开发基于明胶及其复合材料的多功能活性可食用凝胶，并改善其机械性能。
通过将溶菌酶和绿茶提取物负载到明胶/淀粉和明胶/蜡复合凝胶中，开发出了与经典明胶凝胶具有不同物理和活性特性的抗李斯特菌和生物活性复合凝胶。对凝胶的机械性能、溶胀特性、颜色、释放特性以及抗菌和生物活性特性进行了表征。
明胶/蜡凝胶的硬度和切割强度比具有相似硬度和切割强度的明胶及明胶/淀粉复合凝胶高1.3至2.1倍。两种复合凝胶的剪切功比明胶凝胶高1.4至1.9倍。明胶/淀粉凝胶表现出最高的吸水能力。绿茶提取物降低了所有凝胶中可溶性溶菌酶的含量，但复合凝胶中可溶性溶菌酶的含量高于明胶凝胶。所有含溶菌酶的凝胶在肉汤培养基中均抑制了细菌生长，而绿茶提取物仅在明胶/蜡凝胶中表现出抗李斯特菌活性。含绿茶提取物的凝胶表现出抗氧化、抗糖尿病（α-葡萄糖苷酶和α-淀粉酶抑制）、抗高血压（血管紧张素转换酶抑制）和抗增殖活性（对Caco-2人结肠癌细胞）。然而，明胶和明胶/蜡凝胶表现出最高的抗氧化和抗糖尿病活性。明胶/蜡凝胶可防止酚类褐变，而其他凝胶中的绿茶提取物则表现出中度或广泛的褐变。
这项工作清楚地表明了使用明胶/淀粉和明胶/蜡复合材料改善明胶凝胶的机械性能、改变吸水和控释特性的可能性。新型复合凝胶减少了所含多酚的褐变，并表现出抗李斯特菌和生物活性特性。
