Effect of solvents on curcumin as a photosensitizer and its ability to inactivate Aspergillus flavus and reduce aflatoxin B1 in maize kernels and flour. Issue 1 (19th December 2021)

• Record Type: Journal Article
• Authors: Nguenha, Rafael José; Damyeh, Maral Seidi; Hong, Hung Trieu; Chaliha, Mridusmita; Sultanbawa, Yasmina
• Is Part Of: Journal of food processing and preservation. Volume 46:Issue 1(2022)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2021-12-19
• Subjects: Food -- Preservation -- Periodicals; Food industry and trade -- Periodicals; 664.005
• DOI: 10.1111/jfpp.16169
• Languages: English
• ISSNs: 0145-8892

Abstract

Abstract: This study aimed to evaluate the effect of solvent medium, such as ethanol (EtOH), 50% (vol/vol) propylene glycol (PG), 20% (vol/vol) tween‐20 (TW‐20), and 20% (vol/vol) tween‐80 (TW‐80), on curcumin‐mediated photosensitization to inactivate Aspergillus flavus spores in vitro and on the surface of yellow and white maize kernels and flour. Results showed suppression of curcumin phototoxic activity in TW‐20 and TW‐80. However, curcumin‐based photosensitization using EtOH and PG as solvents led to a significant decrease in the colony‐forming ability of A. flavus spores in vitro with up to 2.04 and 3.33 log colony‐forming unit (CFU) reduction, respectively. Interestingly, fungal growth was delayed in photosensitized maize kernels and flour for 14 and 7 days, respectively, which were stored at 25°C. Consequently, no aflatoxin B1 (AFB1) was detected in maize kernels after 20 days of storage at 25°C, and accumulation of the toxin was reduced by 91% in photosensitized flour. Thus, photosensitization is a promising alternative treatment to reduce A. flavus contamination on maize kernels and flour, giving rise to low concentrations of AFB1. This technique has the potential for use in food and feed applications resulting in the reduction of postharvest losses in maize. Novelty impact statement: Photosensitization has emerged as a potential green technology to inactivate microorganisms in food and feed. The properties of curcumin (E100) as a natural photosensitizer have been demonstrated in previous studies. However, due to its insolubility in water in acidic and neutral conditions, ethanol has been widely used for curcumin dissolution, which might limit its application in the food industry. Therefore, this study evaluated the possibility of dissolving curcumin in four solvents and their effect on curcumin phototoxic activity, in vitro and maize kernels and flour. The results showed that propylene glycol, a food‐grade solvent widely used in the pharmaceutical industry, could be an alternative to dissolve curcumin for microbial photoinactivation in the food and feed industry. Curcumin‐mediated photosensitization resulted in decontamination of maize kernels and complete inhibition of aflatoxin accumulation.