High quality lard with low cholesterol content produced by aqueous enzymatic extraction and β‐cyclodextrin treatment

Abstract

New food processing technology is required for food production with high quality and healthfulness. In this study, a novel application was developed to extract lard from pig fatback, a by‐product of the slaughter plant, by an aqueous enzymatic extraction method (AEE). Various proteases with different properties including Alcalase 2.4 L, Neutrase 1.5 MG, Flavourzyme 1000 L, and Protamex were evaluated for their efficiency in oil release and lard qualities. Alcalase 2.4 L was more effective for oil extraction with a yield of 95.19%. A high quality of lard was produced by AEE in comparison with lards produced by conventional extraction methods in aspects of color, acid value, peroxide value, phospholipids, cholesterol, and oxidation stability. A further refinement to reduce cholesterol from lard by β‐cyclodextrin (β‐CD) was developed and the optimal conditions were established. The optimal conditions were 7% β‐CD addition (w/w) to a mixture of equal amount of lard and distilled water at reaction temperature 50°C for about 60 min. The cholesterol content of lard from this refinement process was about 3.2 mg/100 g which was about 93.7% reduction from 51.2 mg/100 g. This simple process by AEE and cholesterol reduction did not affect the composition of fatty acids and construction of triglyceride. Factors that were components of lard or produced during the lard extraction processes were evaluated for their influence on the cholesterol removal. Phospholipids could slightly enhance cholesterol removal, while free fatty acids with saturated or unsaturated aliphatic chains would have inhibitory effects because of their competition with cholesterol for β‐CD.Practical applications: An excellent quality of lard was produced by a novel application of an aqueous enzymatic extraction method (AEE). This lard could be further refined by β‐cyclodextrin for cholesterol reduction. This procedure would be a promising technology to obtain healthy lard and explore animal by‐products for the food industry. This lard with high nutrients could have very broad applications such as in baking, cooking, deep fat frying in food industry.Lard obtained by combination of aqueous enzymatic extraction and β‐cyclodextrin treatment presented high quality and very low cholesterol.