Investigation on the improvement of shea butter yield and quality through enhanced pre-treatment methods: An analytical study on physicochemical properties

Abstract

Shea butter is an organic ingredient used in direct consumption, or the manufacture of products in the food, pharmaceutical, and cosmetic industries. Some pre-treatment processes of shea nuts may not favor the high oil recovery and quality attributes, leading to products that may not conform to market standards for quality, stability, importation, and human consumption. This research emphasizes how roasting or boiling shea nuts for shea butter production enhances its quality by lessening its vulnerability to oxidative instability while simultaneously optimizing oil yield. Shea nuts were collected from an agro-processing company in Ghana. Physicochemical parameters such as refractive index, volatile, acid, iodine, saponification, and peroxide values were analyzed using standard analytical methods. Roasted, boiled, and untreated shea nuts produced a maximum oil yield of 53.53, 48.75, and 47.63 %, respectively. The findings of physicochemical properties of the shea butter samples as time increased from 10 to 50 min for roasted, boiled, and untreated shea nuts showed; an acid value from 8.50 to 17.49 mgKOH/g, 19.4 to 26.46 mgKOH/g and 18.20 mgKOH/g, iodine value from 40.91 – 48.23 gI₂/100 g, 46.17 – 57.93 gI₂/100 g, and 42.9 gI₂/100 g, peroxide value from 2.45 to 4.69 meq/kg, 3.05 to 7.08 meq/kg and 2.15 meq/Kg, refractive index from 1.464 to 1.465, 1.464 to 1.469, and 1.463, saponification value from 181.90 to 187.90 mg KOH/g, 177.70 to 181.55 mg KOH/g and 180.60 mg KOH/g. The quality parameters indicate chances of rancidity. Roasting shea nuts was the optimal condition to produce high yield and quality shea butter than boiled shea nuts. The study recommends that regulatory agencies and consumers conduct regular inspections to verify that shea butter satisfies the appropriate quality and safety criteria for consumption and export.