Abstract

Many personal cleansing products contain microplastics threatening coastal habitats, deep sea, as well as freshwater lakes. Non-pollutant biomasses with natural abrasiveness are potential substitutes for scrub-type cosmetics. This study sought to explore the potential of applying crabwood seed bagasse from Amazonia as an exfoliating agent of skincare soaps. The raw feedstock was characterized by chemical composition and particle size distribution. The morphologies of the crabwood particles and commercial exfoliating agents were compared. Thermal pretreatments were carried out in an attempt to make the particles inert. It was verified that crabwood particles contain above 50% of non-structural organic components in their mass. The high heterogeneity of particle size allowed selecting portions with dimensions comparable to commercial products, between 0.3 and 0.4 mm. The rough surface of crabwood particles was similar to those of other natural plant exfoliating agents suitable for intense skin exfoliation. Thermal pretreatments only partially volatilized non-structural components. The release of oil traces, which contains mainly palmitic and oleic acids, led the pH of the water to an unacceptable level (≤ 5.0), discouraging the direct application of crabwood bagasse in the skin. Nevertheless, when added to non-ionic surfactant based-soaps, pH remains adequate for skincare (≈ 6.0). The smaller particles (average diameter of 0.3 mm) submitted to the most drastic thermal pretreatment, 140 °C for 48 h of exposure, resulted in liquid skincare soaps with better properties. The crabwood particles’ potential to be added as an exfoliating agent in skincare soaps was confirmed.

Graphic Abstract

中文翻译：

---

从Crabwood Waste Bagasse（一种来自Amazonia的天然磨料）获得的护肤皂去角质剂

摘要

许多个人清洁产品所含的微塑料威胁着沿海生境，深海以及淡水湖泊。具有天然磨蚀性的非污染生物质是磨砂型化妆品的潜在替代品。这项研究试图探索将亚马逊河蟹木蔗渣作为护肤皂的去角质剂的潜力。原料通过化学组成和粒度分布表征。比较了crab木颗粒和市售去角质剂的形态。进行热处理以试图使颗粒惰性。已证实，蟹木颗粒在其质量中包含超过50％的非结构有机成分。粒径的高度异质性允许选择尺寸与商业产品相当的部分，在0.3到0.4毫米之间 crab木颗粒的粗糙表面与其他适合强烈剥落皮肤的天然植物去角质剂相似。热处理仅会部分挥发非结构成分。微量油（主要包含棕榈酸和油酸）的释放导致水的pH值达到不可接受的水平（≤5.0），从而阻碍了将crab木蔗渣直接应用于皮肤。然而，当添加到非离子表面活性剂基肥皂中时，pH值仍然足以用于护肤（≈6.0）。较小的颗粒（平均直径为0.3毫米）经受了最剧烈的热处理（140℃，暴露48小时），产生了性能更好的液体护肤皂。证实了山茱particles颗粒有可能作为去角质剂添加到护肤皂中。crab木颗粒的粗糙表面与其他适合强烈剥落皮肤的天然植物去角质剂相似。热处理仅会部分挥发非结构成分。微量油（主要包含棕榈酸和油酸）的释放导致水的pH值达到不可接受的水平（≤5.0），从而阻碍了将crab木蔗渣直接应用于皮肤。然而，当添加到非离子表面活性剂基肥皂中时，pH值仍然足以用于护肤（≈6.0）。较小的颗粒（平均直径为0.3毫米）经受了最剧烈的热处理（140℃，暴露48小时），产生了具有更好性能的液体护肤皂。证实了山茱particles颗粒有可能作为去角质剂添加到护肤皂中。crab木颗粒的粗糙表面与其他适合强烈剥落皮肤的天然植物去角质剂相似。热处理仅会部分挥发非结构成分。微量油（主要包含棕榈酸和油酸）的释放导致水的pH值达到不可接受的水平（≤5.0），从而阻碍了将crab木蔗渣直接应用于皮肤。然而，当添加到非离子表面活性剂基肥皂中时，pH值仍然足以用于护肤（≈6.0）。较小的颗粒（平均直径为0.3毫米）经受了最剧烈的热处理（140℃，暴露48小时），产生了具有更好性能的液体护肤皂。证实了山茱particles颗粒有可能作为去角质剂添加到护肤皂中。

图形摘要