Effect of Chia seed oil supplemented ice-cream on lipid profile

Chia seeds contain high levels of lipids (34.4%) and are rich in Omega-3, Omega-6 and Omega-9, which constituted 62, 17.4 and 10.5% of the total lipids, respectively. Milk fat is a major source of saturated fatty acids and cholesterol. Milk fat contains more than 70% saturated fatty acids, about 26% monounsaturated fatty acids and less than 4% polyunsaturated fatty acids. According to recommendations provided by American Heart Association (AHA) the intake of saturated fats should be limited from 7-10 % of total daily calories. . As milk fat is a big birthplace for cardiovascular diseases, so a mark able decrease in mortality can be achieved by modifying the fatty acid profile of dairy products. It can be achieved by replacing saturated fatty acid content with unsaturated fatty acids. Production of ice cream with vegetable fat instead of animal fat is a way to produce a nutritionally healthier and low cholesterol product. Because of the highly unsaturated nature of the oil, the seeds probably contain potent lipid antioxidants . Chia seed contains the highest known percentage of α-linolenic acid (ALA) of any plant source. Recent studies shows that chia seed possesses the highest amount of PUFA content, more than 80.5%and the best n-6/n-3 ratio compared with flaxseed and perilla. ALA leads to small but significant increases in EPA and DPA in humans (Nieman et al. 2009).Nutritionally and potentially therapeutic value of a food plays a key role in the development of new value-added products that are manufactured for health-conscious consumers. As omega-3 and omega -6 fatty acids are present in chia seed oil abundantly; it can be incorporated in ice cream as a replacer of cream to have its beneficial effects. It may be helpful in lowering the triglycerides and cholesterol level of blood which in turn results in low blood pressure and heart related diseases (Heuer et al. 2002). Project was designed in such a manner that fat of ice cream was replaced with chia seed oil in different proportions i.e., 25%, 50%,75%,100%. After physico- chemical and sensory evaluation of ice cream ,best treatment was selected and used for efficacy trials. After baseline line study and thorough inclusion criteria 10 individuals were selected and divided into two groups .One group treated as control and the other was given chia seed oil supplemented (50%) ice cream. Significant decrease in cholesterol level was observed in the treated group .18% decrease in cholesterol level was observed at 40th day followed by 8% at 20th day. Similarly 20% decrease in LDL cholesterol with 14% increase in HDL cholesterol. It was recommended that further trials be conducted with sophisticated techniques to completely replace saturated fat in ice cream with unsaturated fats and to study its effect in hyperglycemia and oxidative stress.奇亚籽（Chia seeds）脂质含量丰富，达34.4%，同时富含Omega-3、Omega-6与Omega-9脂肪酸，三者分别占总脂质的62%、17.4%与10.5%。乳脂是饱和脂肪酸与胆固醇的主要来源，其饱和脂肪酸占比超过70%，单不饱和脂肪酸约占26%，多不饱和脂肪酸占比不足4%。根据美国心脏协会（American Heart Association, AHA）的推荐，每日饱和脂肪摄入量应控制在总热量的7%~10%。由于乳脂是心血管疾病的重要诱因，因此通过调整乳制品的脂肪酸组成，可显著降低心血管疾病死亡率。而实现这一目标的途径之一，便是用不饱和脂肪酸替代饱和脂肪酸。以植物脂肪替代动物脂肪生产冰淇淋，即可制备营养更健康、胆固醇含量更低的产品。奇亚籽油脂具有高度不饱和的特性，因此其可能含有强效的脂质抗氧化剂。奇亚籽是目前已知所有植物来源中α-亚麻酸（α-linolenic acid, ALA）占比最高的物种。近期研究表明，与亚麻籽、紫苏相比，奇亚籽的多不饱和脂肪酸（polyunsaturated fatty acid, PUFA）含量最高，超过80.5%，且n-6/n-3脂肪酸比例最优。人体摄入ALA后，可使EPA和DPA水平出现小幅但显著的升高（Nieman等，2009）。食物的营养与潜在治疗价值，对于面向健康关注型消费者开发高附加值新产品具有关键作用。由于奇亚籽油中富含Omega-3与Omega-6脂肪酸，因此可替代奶油添加至冰淇淋中，以发挥其有益功效。这可能有助于降低血液甘油三酯与胆固醇水平，进而实现低血压与降低心脏相关疾病风险的效果（Heuer等，2002）。本研究的实验设计如下：以25%、50%、75%、100%四种不同比例的奇亚籽油替代冰淇淋中的脂肪。通过对冰淇淋进行理化与感官评价后，筛选出最优配方用于功效验证试验。在完成基线研究并严格遵循纳入标准后，共招募10名受试者并分为两组：对照组与奇亚籽油补充（50%替代比例）冰淇淋干预组。干预组的胆固醇水平出现显著降低：第40天时胆固醇水平下降18%，第20天时下降8%；低密度脂蛋白（LDL）胆固醇下降20%，同时高密度脂蛋白（HDL）胆固醇升高14%。最后建议：未来可采用更精密的技术开展进一步试验，以完全用不饱和脂肪替代冰淇淋中的饱和脂肪，并研究其对高血糖与氧化应激的影响。