Co-valorization of agro-industry by-products: effect of citrus oil on the quality of soap derived from palm fatty acid distillate and spent bleaching clay

Abstract

This study deals with the co-valorization of spent bleaching clay (SBC) and palm fatty acid distillate (PFAD) –by-products of palm oil refining plants- through soap manufacture. Obtained SBC and PFAD samples show differing acidity and saponification values depending on fatty acids and acylglycerols content. Soaps are prepared using the stoichiometric amount of NaOH, under the varying proportion of water introduced through the basic solution. The mixing SBC and PFAD (ratio 1:3), the reaction completion (92.5%) is surprisingly higher than expected, indicating a synergistic effect on the course of the saponification reaction. The water is also a critical parameter, 30% w/w of added water allowing the highest yield. When testing for cleaning efficiency the products having the highest soap content, those from individual by-products give a low microbial count reduction after hand-washing (30-37%). But a much better score (74%) is obtained when using SBC:PFAD soap mixtures. This improvement could be due to abrasive and absorption effects of the clay, combined with the high soap content. The acceptability through a panel test is good for all soaps when formulated with citrus oil. The most active product corresponds to a SBC:PFAD ratio close to the production one in refining plants. Therefore these results provide an easy way for co-valorising these by-products, after further optimizing the saponification reaction in this complex triphasic medium (aqueous solution, oil, clay).

Developing a soft margarine with modified fatty acid profile having low trans fatty acids

“…Peroxide values of palm stearin, rice bran oil, and soybean oil were lower than that of the oil mixture. This shows the governing effect of oxidation on fatty acids, wellknown to affect the physicochemical properties on refining and mixing oils (Punvichai & Pioch, 2019a, 2019b. Fatty acid compositions of the samples are given in Table 3.…”

“…The analysed fatty acid compositions of the oils in this study are shown in Table 3. Palm stearin shows larger proportions of saturated and monounsaturated fatty acids (64.81% and 29.66%, respectively) than of polyunsaturated fatty acids (Punvichai & Pioch, 2019a, 2019b). But, palm stearin contains less MUFA (29.66%) than rice bran oil (41.82%).…”

“…The product was evaluated for colour, general appearance, odour, texture, and overall acceptability. The 9‐point Hedonic scale was used: 9 = like extremely, 7 = good, 5 = neither like nor dislike, 3 = poor, and 1 = dislike extremely (modified from Punvichai & Pioch, 2019a, 2019b). A 5‐point just‐about‐right scale was used to determine the unsuitability of each tested property (Punvichai & Pioch, 2019a, 2019b; Chailangka et al ., 2023).…”

Bio-Insecticidal Potential of Tangerine Peel Oil Against Greenhouse Whitefly: A Green Biopesticide Candidate

“…The overproduction of some foods, such as tangerines, brings unpleasant effects on health and the environment, especially in the areas surrounding municipal landfills. Therefore, finding some alternatives to recover these crop wastes is necessary [45][46][47]. In the case of mandarin, it might be convenient to find economically feasible ways to use the tangerine peel to produce essential oils with high contents of bioactive substances such as d-limonene [48].…”