Application of lime peel oil composite nanoemulsion to prevent toxigenic fungi in nuts.

Food byproduct oils may have antimicrobial impacts when used in coating and preservation. Nuts are known to suffer from toxigenic fungi and their related mycotoxins. The present study utilized lime oil emulsion to minimize fungal infection and reduce aflatoxin B1 (AFB1). Besides, it evaluated lime oil's impact on nuts' protection against oxidation and deterioration during storage. Lime oil was extracted using hydrodistillation, and gas chromatography (GC-MS) evaluated volatile constituents. Oil was loaded into a composite emulsion of whey protein, Arabic gum, gelatin, and carboxymethyl cellulose. The antimicrobial and antifungal properties of the nut-coating emulsion were evaluated. A simulated Aspergillus flavus infection experiment evaluated composite resistance for fungal infection and AFB1 production. Oxidation and acidity changes in nuts oil composition were evaluated by proximate analysis, fatty acid composition, and induction period. The oil majority was recorded for terpenes and monoterpenes, including limonene (44.69 ± 2.11%). The emulsion was characterized by zeta potential (-21.16 ± 1.28 mV), stability (99.61 ± 0.02%), and polydispersity index (0.41 ± 0.05). Antimicrobial properties recorded a high antibacterial inhibition zone (up to 28.37 ± 0.11 mm) and anti-mycotoxigenic fungi (up to 37.61 ± 0.24 mm). For the simulated experiment, fungal growth reduction ranged between 78.02% for filmed-peanut and 84.5% for filmed-almond, while AFB1 was not detected in filmed hazelnut and almond. During the one-year storage of samples, there was a slight change in nut oil composition and oxidation progress in filmed nuts, while there was a significant change in non-filmed nuts. The result recommended lime-composite as an edible nut coating that prevents aflatoxigenic contamination, oxidation changes, and improved shelf life.

Effect of Refining and Fractionation Processes on Minor Components, Fatty Acids, Antioxidant and Antimicrobial Activities of Shea Butter.

Shea butter is becoming increasingly popular in foods, cosmetics and pharmaceutical products. This work aims to study the effect of the refining process on the quality and stability of fractionated and mixed shea butters. Crude shea butter, refined shea stearin, olein and their mixture (1:1 w/w) were analyzed for fatty acids, triacylglycerol composition, peroxide value (PV), free fatty acids (FFA), phenolic (TPC), flavonoid (TFC), unsaponifiable matter (USM), tocopherol and phytosterol content. Additionally, the oxidative stability, radical scavenging activity (RSA), antibacterial and antifungal activities were evaluated. The two main fatty acids in the shea butter samples were stearic and oleic. The refined shea stearin showed lower PV, FFA, USM, TPC, TFC, RSA, tocopherol and sterol content than crude shea butter. A higher EC50 was observed, but antibacterial activity was much lower. The refined olein fraction was characterized by lower PV, FFA and TFC in comparison with crude shea butter, but USM, TPC, RSA, EC50, tocopherol and sterol content was unchanged. The antibacterial activity was higher, but the antifungal activity was lower than those of crude shea butter. When both fractions were mixed, their fatty acid and triacylglycerol composition were similar to those of crude shea butter, but other parameters were different.

A Comprehensive Study of Lupin Seed Oils and the Roasting Effect on Their Chemical and Biological Activity.

The present investigation aimed to study the impact of roasting on the chemical composition and biological activities of sweet and bitter lupin seed oils. Lupin oils were extracted using petroleum ether (40-60) with ultrasonic assisted method. Lupin Fatty acids, phytosterols, carotenoids, and total phenolic contents were determined. In addition, antioxidant, antimicrobial, and antifungal activities were evaluated. The results showed a ratio between 7.50% to 9.28% of oil content in lupin seed. Unroasted (bitter and sweet) lupin oil contained a high level of oleic acid ω9 (42.65 and 50.87%), followed by linoleic acid ω6 (37.3 and 34.48%) and linolenic acid ω3 (3.35 and 6.58%), respectively. Concerning phytosterols, unroasted (bitter and sweet lupin) seed oil reflected high values (442.59 and 406.18 mg/100 g oil, respectively). Bitter lupin oil contains a high amount of phenolics, although a lower antioxidant potency compared to sweet lupin oil. This phenomenon could be connected with the synergistic effect between phenolics and carotenoids higher in sweet lupin oil. The results reflected a more efficiently bitter lupin oil against anti-toxigenic fungi than sweet lupin oil. The roasting process recorded enhances the antimicrobial activity of bitter and sweet lupin seed oil, which is linked to the increment in bioactive components during the roasting process. These results concluded that lupin oil deems a novel functional ingredient and a valuable dietary fat source. Moreover, lupin oil seemed to have antifungal properties, which recommended its utilization as a carrier for active-antifungal compounds in food products.