Use of Natural Antioxidants from Newfoundland Wild Berries to Improve the Shelf Life of Natural Herbal Soaps

Abstract

Antioxidants are important bio-regulators and suppressors of oxidation and are useful in enhancing the shelf life of consumer products. Formulated natural herbal soaps contain ingredients with antioxidant activities, but it is unknown how this influences shelf life. Herein, we evaluated whether natural additives or wild berry extracts were effective in improving the quality of natural herbal soaps. Three natural soaps, base bar (BB), forest grove (FG), and hibiscus rosehip (HR), were formulated using several wild berry extracts or natural additives and evaluated against similar commercial brands. The total phenolic content (TPC) of BB and FG infused with partridgeberry and HR with rosemary was 35.22, 44.72, and 33.26 µmole quercetin equivalent/g soap, while the total antioxidant activity (TAA) was 125.20, 119.23, and 126.94 µmole Trolox equivalent/g soap, respectively. Conversely, the commercial brand (BSG) with the highest TPC (56.24 µmole) contained lower TAA (59.68 µmole). As expected, the TPC and TAA of natural soaps were strongly correlated, and the majority (55–82%) of the polyunsaturated di/triacylglycerols remained unsaponified. Some extracts were inhibitory, while others promoted microbial growth. The results indicate that natural antioxidants from some Newfoundland wild berries have applications in improving the shelf life of natural herbal soaps, but care must be taken with the choice of berry used in the final soap formulation.

Physicochemical Characterization of Home-Made Soap from Waste-Used Frying Oils

“…It is worth mentioning that cold saponification of oils can, in practice, hardly be 100% completed, but since this topic has been poorly studied, there is very little data on it. In the work of Adigun (2019), the mentioned levels of saponified fatty acids in home-made soaps made by cold saponification ranged between 70% and 85% [19]. Hence, as the constituents of final soap products, we also have triacylglycerols, diacylglycerols, monoacylglycerols and free fatty acids, mainly consisting of unsaturated fatty acids [13].…”

“…Frying of oils was carried out in laboratory conditions by consecutive heating the oil to 200 • C and cooling it for 20 min at room temperature (three cycles of heating and cooling were repeated). The soaps were made according to the work of Adigun (2019), with slight modifications [19]. The recipe consisted of 280 g of oil, 36.04 g of NaOH for olive oil soap and 34.10 g of NaOH for rapeseed-palm oil soap and 106.40 g of distilled water.…”

Environmental impact of increased soap consumption during COVID-19 pandemic: Biodegradable soap production and sustainable packaging

“…Moreover, biosurfactants are safe and have a variety of biological functions, making them a good option in pharmaceutical and biomedical domains. Since information on the probable toxicity of synthetic antioxidants is emerging, it has been attempted to replace synthetic antioxidants with natural additives, particularly those obtained from plant resources, spices, vegetables, culinary herbs, and agro-industry by-products of oilseeds and fruits, containing high levels of phenolics and other active ingredients ( Adigun et al, 2019 ; Villalobos-Delgado et al, 2019 ). Adigun et al evaluated the effects of antioxidants from Newfoundland wild berries on natural herbal soap's shelf life to preserve against lipid oxidation and microbial growth.…”

“…According to their research findings, considerable amounts of phenolics, unsaponified neutral lipids, and antioxidants were retained in soaps made of natural additives and wild berry extracts with cold saponification. Furthermore, there was a higher level of total phenolic content and antioxidant activities in natural herbal soaps compared to commercial types, which potentially improves their shelf life ( Adigun et al, 2019 ). Table 2 shows recent studies on the production of biodegradable and natural soaps and the replacement of synthetic ingredients with sustainable materials.…”

Reused Plant Fried Oil: A Case Study with Home-Made Soaps

“…The samples were labeled according to Table 1. The soaps were made using the cold saponification method reported by Adigun et al [17] with slight modifications. An amount of 130 g of filtered oil was mixed with 66.92 g of 26% (w/w) NaOH water solution using the blender (3-5 min).…”