Use of citrus flavanones to prevent aflatoxin contamination using response surface methodology

Targeting of Antifungal Metabolites from Grapevine Byproducts by UPLC-HRMS/MS Approaches Using Bioactivity-Based Molecular Networking

This study focuses on countering Fusarium graminearum, a harmful fungal pathogen impacting cereal crops and human health through mycotoxin production. These mycotoxins, categorized as type B trichothecenes, pose significant health risks. Research explores natural alternatives to synthetic fungicides, particularly investigating phenolics in grapevine byproducts. Thirteen eco-extracts from five French grape varieties (Merlot, Cabernet Sauvignon, Sauvignon blanc, Tannat, and Artaban) exhibited substantial antifungal properties, with ten extracts displaying remarkable effects. Extracts from grapevine stems and roots notably reduced fungal growth by over 91% after five days. Through UHPLC-HRMS/MS analysis and metabolomics, the study identified potent antifungal compounds such as ampelopsin A and cyphostemmin B, among other oligomeric stilbenes. Interestingly, this approach showed that flavan-3-ols have been identified as markers for extracts that induce fungal growth. Root extracts from rootstocks, rich in oligostilbenes, demonstrated the highest antifungal activity. This research underscores grapevine byproducts' potential both as a sustainable approach to control F. graminearum and mycotoxin contamination in cereal crops and the presence of different metabolites from the cultivars of grapevine, suggesting different activities.

Aflatoxins posing threat to food safety and security in Pakistan: Call for a one health approach

Aflatoxins are among the most important mycotoxins due to their widespread occurrence and adverse impacts on humans and animals. These toxins and/or their metabolites cannot be destroyed with cooking or boiling methods. Therefore, consumption of aflatoxin-contaminated food may lead to impaired growth, compromised immunity, stomach and liver cancer, and acute toxicity. These adverse effects along with food wastage might have detrimental consequences on a country's economy. Several studies from Pakistan reported a high prevalence of aflatoxins in food and feed commodities (Range; milk = 0.6-99.4%, cereals, and grains = 0.38-41%, animal feed = 31-100%). Notably, Pakistan reported very high figures of impaired child growth-stunted 40.2%, wasted 17.7% and underweight 28.9%-that could be associated with the higher aflatoxin prevalence in food items. Importantly, high aflatoxins prevalence, i.e. 100%, 69% and 60.5%, in children has been reported in Pakistan. Food and feed are more prone to aflatoxin contamination due to Pakistan's hot and humid climate; however, limited awareness, inadequate policy framework, and weak implementation mechanisms are the major obstacles to effective control. This review will discuss aflatoxins prevalence, associated risk factors, adverse health effects, required regulatory regime, and effective control strategies adopting the One Health approach to ensure food safety and security.

Citrus flavonoids against Fusarium verticillioides in post-harvest maize: Minimization of fumonisins and alteration of fungal ultrastructure

AIMS

To minimize fumonisins (FBs) accumulation by Fusarium verticillioides in post-harvest maize, using flavonoids obtained from citrus residues: naringin (NAR), neohesperidin (NEO), quercetin (QUER), and its mixtures.

METHODS AND RESULTS

Response surface methodology with Box-Behnken design was applied in maize at 0.98 and 0.95 a_w . The optimal mixture found, composed of 0.40 mmol kg^-1  NAR, 0.16 mmol kg^-1  NEO and 0.37 mmol kg^-1 QUER, reduced the accumulation of FBs B1, B2, and B3 by 88 ± 6%, 90 ± 6% and 85 ± 5%, respectively, when applied to maize at 0.98 a_w . The mentioned mixture led to a 54 ± 9% reduction of fumonisin B1 accumulation in maize adjusted to 0.95 a_w . These flavonoids applied individually and as a mixture, affected the structure of both the cell wall and the cytoplasm of F. verticillioides. The cell wall lost rigidity and the cells appeared highly deformed, with ruptured plasmalemma and disrupted endomembranes.

CONCLUSIONS

It was possible to diminish the accumulation of FBs in maize by a highly toxigenic Fusarium strain, producing severe damage to its ultrastructure.

SIGNIFICANCE AND IMPACT OF STUDY

The results indicate the possible use of flavonoids from citrus industry residues as natural and environmentally friendly antifungal agents to restrain the accumulation of FBs in stored maize.

Optimization of a rice cooking method using response surface methodology with desirability function approach to minimize pesticide concentration

Rice is contaminated with pesticides applied in pre and post-harvest. These contaminations could be reduced through household operations like washing and cooking. Therefore, in the present research, a pre-soaking rice cooking method was used to reduce pesticides residues. Response Surface Methodology with Central Composite Design was applied to minimize pesticides concentration by choosing the best soaking time and water:rice grain relation before cooking. A quadratic polynomial equation was obtained. Desirability function approach gave the optimal cooking conditions as 14 h soaking time and water:rice grain relation of 3. This process allowed a pesticide elimination of 100.0%, 93.5%, 98.4%, 98.5%, 99.0%, and 95.0%, of azoxystrobin, cyproconazole, deltamethrin, epoxiconazole, kresoxim-methyl and penconazole, respectively.

Anti-fungal activity of phenolic sweet orange peel extract for controlling fungi responsible for post-harvest fruit decay

There is a growing interest in finding safe and natural anti-microbial compounds as a valid alternative to conventional chemical treatments for managing post-harvest fruit diseases. This study investigated the anti-fungal capacity of orange peel polyphenolic extract (OPE) against three relevant post-harvest fungal pathogens, Monilinia fructicola, Botrytis cinerea and Alternaria alternata. OPE extract at 1.5 g/L inhibited (100%) the mycelial growth and conidial germination of the three target fungi. At lower concentration, the effect varied, depending on the dose applied and target fungi. When the anti-fungal activity of the main phenolic compounds in sweet orange peel, namely, the flavonoids (naringin, hesperidin and neohesperidin) and phenolic acids (ferulic and p-coumaric), were evaluated, ferulic acid and p-coumaric acid displayed significantly higher inhibitory capacity in synthetic medium, while the activity of flavonoids was limited. Synergism between compounds was not detected, and the inhibitory activity of OPE may be attributed to an additive effect of phenolic acids. Interestingly, in peach-based medium, ferulic acid remained active against M. fructicola and A. alternata and was more efficient than p-coumaric to control B. cinerea. These results highlight peel orange waste as an excellent source of anti-fungal compounds, suggesting the possibility of using ferulic acid or ferulic acid-rich extracts, either alone or in combination with other post-harvest treatment, as a natural alternative to reduce post-harvest losses and, also, enhance the shelf-life of fruit.

Efficacy of different citrus essential oils to inhibit the growth and B1 aflatoxin biosynthesis of Aspergillus flavus

Food contamination by aflatoxin B1 (AFB1), produced by mycotoxigenic strains of Aspergillus spp., causes severe medical and economic implications. Essential oils (EOs) are mixtures of eco-friendly natural volatile substances. Their ability to inhibit fungal growth has been investigated, while no data are available about their efficacy in inhibition of AFB1 biosynthesis. This study investigates the efficacy of five different citrus EOs to inhibit the growth and AFB1 synthesis of A. flavus through in vitro tests for a future application in food matrices. AFB1 detection was carried out by LC-ESI-TQD analytical approach. Lemon (Citrus limon (L.) Burm. f.), bergamot (Citrus bergamia Risso), and bitter orange (Citrus aurantium L.) EOs were the most effective causing a 97.88%, 97.04%, and 96.43% reduction in mycelial growth, respectively. Sweet orange and mandarin EOs showed the lowest percentage of mycelial growth reduction. Citrus EOs showed different capacity of AFB1 inhibition (lemon > bitter orange > bergamot > sweet orange > mandarin). Our results showed a dose-dependent antifungal activity of lemon, bitter orange, and bergamot EOs which at 2% (v/v) inhibited both mycelium growth and AFB1 genesis of A. flavus. Our results show that EOs' use can be a pivotal key to recovery and reuse of citrus fruit wastes and to be used as eco-friendly fungicides for improvement of food safety. The use of EOs obtained at low cost from the residues of citric industry presents an interesting option for improving the profitability of the agriculture.

Innovative technologies to manage aflatoxins in foods and feeds and the profitability of application - A review

Aflatoxins are mainly produced by certain strains of Aspergillus flavus, which are found in diverse agricultural crops. In many lower-income countries, aflatoxins pose serious public health issues since the occurrence of these toxins can be considerably common and even extreme. Aflatoxins can negatively affect health of livestock and poultry due to contaminated feeds. Additionally, they significantly limit the development of international trade as a result of strict regulation in high-value markets. Due to their high stability, aflatoxins are not only a problem during cropping, but also during storage, transport, processing, and handling steps. Consequently, innovative evidence-based technologies are urgently required to minimize aflatoxin exposure. Thus far, biological control has been developed as the most innovative potential technology of controlling aflatoxin contamination in crops, which uses competitive exclusion of toxigenic strains by non-toxigenic ones. This technology is commercially applied in groundnuts maize, cottonseed, and pistachios during pre-harvest stages. Some other effective technologies such as irradiation, ozone fumigation, chemical and biological control agents, and improved packaging materials can also minimize post-harvest aflatoxins contamination in agricultural products. However, integrated adoption of these pre- and post-harvest technologies is still required for sustainable solutions to reduce aflatoxins contamination, which enhances food security, alleviates malnutrition, and strengthens economic sustainability.