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Effectiveness of synthetic and potential natural antioxidants in improving the stability of sheep's anhydrous butter fat during long‐term storage

Amr, Ayed S
Journal of the science of food and agriculture 1991 v.55 no.1 pp. 75-85
Ruta graveolens, ambient temperature, butter, butylated hydroxyanisole, butylated hydroxytoluene, fatty acid composition, fennel, free fatty acids, glass, heat, hens, jars, milk fat, oleic acid, oxygen, peroxide value, rancidity, rosemary, sage, sheep, storage, storage quality, storage time, superoxide anion, synergism, turmeric
Sheep's anhydrous butter fat as prepared by including separately heat grits, turmeric, rosemary, sage, rue and fennel at a level of 75 g dry matter kg⁻¹ butter. The product as stored at room temperature in clear glass jars for a period of one year. The storage stabilities of the anhydrous butter fat samples ere compared ith a control and ith a sample treated ith a 1:1 mixture of BHA and BHT at a level of 0.25 g kg⁻¹. Both storage time and type of treatment had highly significant effects (P⩽0.01) on the peroxide value and free fatty acid content of the product. None of the treatments succeeded in keeping the peroxide value belo 5 mEq O₂ kg⁻¹ beyond the fourth month of storage. The BHA‐BHT mixture and rosemary helped extend the peroxide induction period to 10 and 6 months respectively. Turmeric and heat grits ere as effective as BHA‐BHT in controlling the oxidative rancidity during the first four months of storage. The rest of the herbs exhibited a pro‐oxidant effect throughout the study hen they ere used separately. In a second experiment, some cases of positive synergistic interactions ere observed beteen turmeric and heat grits on one hand and the herbs used in the study on the other. This pattern as not regular as negative interactions ere also observed in some other cases. Free fatty acid content of all the samples remained belo 10 g kg⁻¹ as oleic acid; hoever, fennel had a significant (P⩽0.05) effect on controlling the evolution of free fatty acids.