Enzyme produced structured lipids for infant formula

Summary

We prepared structured lipid from amaranth oil enriched with palmitic acid specifically at the sn-2 position for possible application in infant formlae. The physcial and chemical characteristics of DHA-containing SL support their application as a pontential fat analog for milk-based infant formula.

Situation

The breast milk is highly nutritious for infants. Lipids in breast milk represent an important source of energy (approximately 50% of total energy) and essential fatty acids required by infants. Palmitic acid accounts for the majority of the saturated fat portion in breast milk with over 60% by weight esterified at sn-2 position. Breast milk may also naturally contain docosahexaenoic acid, DHA (~0.06-0.4%) but the variations in content depend on the mother's diet and metabolism. Indeed, the level of DHA in USA mother's breast milk is so low that supplementation is encouraged. The European Society for Pediatric Gastroenterology, Hepatology and Nutrition (ESPGHAN) recommends levels of 0-0.5% DHA in infant formula. Infant formulas have been developed to complement and/or substitute optimum nutrition from breast milk. Infant formulas intended for healthy term infants should mimic the composition of breast milk from healthy mothers. The fat portion in commercial infant formulas is usually achieved with vegetable oils such as coconut, soybean, sunflower and corn oils. Blends of these oils are readily used to balance the fatty acid (FA) content of the final product. Enzymatic structuring can be used to produce infant formula fat analogs. The purpose of our study is to use enzymatic interesterification techniques to modify underutilized amaranth oil into a structured lipid (SL), by increasing its palmitic acid content at sn-2 position and incorporating DHA, so it can be partially or complementarily used in milk-based infant formulas to deliver a lipid component more similar to breast milk.

Response

Underutilized amaranth oil was used to prepare structured lipid as fat analog for milk-based infant formula. Amaranth oil contains fatty acids leveles similar to those from breast milk.

Impact

The aim of this study was to use enzymatic interesterification techniques to modify underutilized amaranth oil as a structured lipid (SL) by increasing its palmitic acid content at sn-2 position and incorporating docosahexaenoic acid (DHA). This SL can be partially or complementarily used in milk-based infant formulas to deliver a lipid component similar to breast milk. Amaranth oil was modified by enzymatic interesterification in two stages. First, palmitic acid content was increased specifically at the sn-2 position to resemble breast milk triacylglycerols (TAGs) using Novozym 435 lipase. Then DHA was incorporated, mainly at the sn-1,3 positions using Lipozyme RM IM, a sn-1,3 specific lipase. An optimization model was developed to determine the exact parameter combinations to incorporate a specific amount of DHA (1.0-2.5%). The model suggestions were used for a gram scale interesterification to yield the expected product. The final SL composition was: palmitic 33.9%, stearic 2.8%, oleic 23.3%, linoleic 37.3%, linolenic 0.7%, and docosahexaenoic 1.9% acids. The original amaranth oil and the final SL were characterized by determining the fatty acid composition, melting profile, chemical characteristics, oxidative stability (peroxide, p-anisidine, and total oxidation values), phytosterols, tocopherols and squalene contents. The physical and chemical characteristics determined in this study support the potential application of DHA-containing customized amaranth oil (DCAO) as a partial fat substitute or complement for milk-based infant formula.

State Issue

Food, Nutrition and Health

Details

• Year: 2009
• Geographic Scope: University
• County: Clarke
• Program Areas:
  • Agriculture & Natural Resources