Extraction of valuable egg yolk proteins for uses as functional food ingredients

鸡蛋是一种用途广泛的食品配料。对高质量蛋清蛋白的需求不断增长，导致蛋黄供过于求，往往以低得多的价格出售，这可能影响整个鸡蛋行业的盈利能力。因此，除了在蛋黄酱和沙拉酱中的传统应用之外，迫切需要多样化蛋黄的利基市场用途。我们的行业合作伙伴展望，蛋黄用途的多样化将帮助他们扩展到增值功能食品市场。研究的总体目标是开发一种有效的光维素提取方法，并探索其作为抗骨质疏松症功能性食品成分的潜在应用。采用酶助水提法去除蛋黄中的脂质，采用膜处理法回收磷脂；将制备去磷酸化的光维素（dPV）和光维素水解物（PVH）。本文将研究不同形态的光维素对生物活性的影响及其作用机制。根据加拿大卫生部的数据，骨质疏松症影响了约140万加拿大人，给加拿大医疗保健系统造成了超过23亿美元的损失。骨质疏松症会导致毁容，丧失行动能力和独立性，降低自尊，最终降低生活质量。然而，据报道，用于治疗骨质疏松症的药物会增加患癌症的风险，并影响心血管疾病。因此，开发磷维素作为一种功能性食品成分可能为这一日益增长的流行病提供更好的长期解决方案，并为加拿大带来可观的经济和社会效益。磷维素抗骨质疏松作用的确立，将扩大蛋黄蛋白的使用和市场份额，提高蛋业的盈利能力。

Egg is a versatile food ingredient. The growing demand for high quality egg white protein has led to an over-supply of egg yolk that often is sold at much lower price which can affect the profitability of the egg industry as whole. Thus, there is an urgent need to diversify yolk uses for niche markets beyond its traditional applications in mayonnaise and salad dressing. Our industry partners envision that diversification of egg yolk uses will help them expand into value-added functional food market. The overall objectives are to develop an efficient method of phosvitin extraction and to explore its potential applications as a functional food ingredient against osteoporosis. Lipids in egg yolk will be removed by enzyme-assisted aqueous extraction and phosvitin will be recovered using membrane processing; dephosphorylated phosvitin (dPV), and phosvitin hydrolysate (PVH), will be prepared. Effects of different forms of phosvitin on the biological activities, and their mechanisms of action will be studied. According to Health Canada, osteoporosis affects ~1.4 million Canadians and costs over $2.3 billion to the Canadian healthcare system. Osteoporosis can lead to disfigurement, loss of mobility and independence, lowered self-esteem and, ultimately, reduced quality of life. Pharmaceutical drugs for treatment of osteoporosis however are reported to increase the risk of cancer and affect cardiovascular diseases. Therefore, developing phosvitin as a functional food ingredient might provide a better long-term solution for this growing epidemic with substantial economic and social benefits to Canada. Establishment of the role of phosvitin against osteoporosis will expand the usage of egg yolk protein and its market share, and enhance the profitability of the egg industry.