Exogenous β‐aminobutyric acid application attenuates Aspergillus decay, minimizes aflatoxin B₁ accumulation, and maintains nutritional quality in fresh‐in‐hull pistachio kernels

Abstract

BACKGROUND Pistachio fruits suffer from postharvest decay, caused by Aspergillus flavus. This results in aflatoxin B1 (AFB1) accumulation in kernels, which is hazardous for human health due to its carcinogenic activity. In this study, the mechanism used by exogenous β‐aminobutyric acid (BABA) treatment for attenuating Aspergillus decay, minimizing aflatoxin B1 (AFB1) accumulation, and maintaining nutritional quality in fresh‐in‐hull pistachio kernels, infected by A. flavus during storage at 25 °C for 18 days, was investigated. RESULT Results of an in vivo assay showed that the spore germination and germ tube elongation of A. flavus was repressed by BABA treatment at 7.5 mM. Aspergillus decay accompanied by AFB1 accumulation was also minimized in fresh‐in‐hull pistachio kernels treated with BABA at 7.5 mM and infected by A. flavus. Fresh‐in‐hull pistachio kernels, infected by A. flavus, treated with BABA at 7.5 mM, also exhibited higher phenol and flavonoid accumulation and 2,2‐diphenyl‐1‐picrylhydrazyl (DPPH) scavenging capacity accompanied by higher phenylalanine ammonia lyase (PAL) enzyme activity. CONCLUSION Promoting phenylpropanoid pathway activity with higher PAL enzyme activity in fresh‐in‐hull pistachio kernels treated with BABA may not only reduce Aspergillus decay in kernels by cell wall fortification but also may be favorable for maintaining the kernels’ nutritional quality through its effects on ROS scavenging capacity. As oxidative stress, represented by ROS accumulation, is responsible for A. flavus growth and AFB1 accumulation, higher phenol and flavonoid accumulation in fresh‐in‐hull pistachio kernels treated with BABA may be beneficial for attenuating Aspergillus decay and minimizing AFB1 accumulation. © 2019 Society of Chemical Industry

Effect of exogenous melatonin treatment onAspergillusdecay, aflatoxin B1 accumulation and nutritional quality of fresh “Akbari” pistachio fruit

“…Then, the fruit was inoculated with 100 μL of A. flavus at a spore concentration of 5 × 10 5 spore mL ‐1 . After inoculation, the fruits were kept in conventional polyethylene packaging and stored at room temperature (25 ± 2°C) for 18 days (Aghdam et al., 2020). Fresh pistachio fruits Aspergillus decay (%) and kernels AB1 content were determined after 18 days at 25°C.…”

“…Pistachio kernels are valuable for human health due to having higher health‐promoting phytochemicals such as unsaturated fatty acids and polyphenols (Gheysarbigi et al., 2020; Rusu et al., 2019; Sheikhi et al., 2019). Recently, the world consumption of fresh pistachio fruit has been continuously growing, thus the market demand for these commodities is also increasing in some regions of the world (Aghdam et al., 2020; Molamohammadi et al., 2020). Aflatoxin B 1 (AB 1 ) accumulation as carcinogenic and teratogenic mycotoxin in pistachio fruits during Aspergillus flavus infection have been considered as a risk for human health which confines kernels consumption (Fountain et al., 2015; Nayak et al., 2017).…”

“…Also, Aghdam et al. (2020) reported that β‐aminobutyric acid treatments reduced AB1 accumulation by attenuating fungal decay and decreasing reactive oxygen species (ROS) levels of fresh pistachio kernels during storage life.…”

β-aminobutyric acid (BABA): towards understanding its biosynthesis, localization and hormonal regulation in "Arabidopsis thaliana"

“…BABA application, for example, induced resistance against Aspergillus flavus in harvested pistachio fruits, reducing the fungal aflatoxin accumulation in kernels as well. Furthermore, BABA application boosted higher phenol and flavonoid production in pistachio kernels, and also an increased PAL enzymatic activity (Aghdam et al, 2020). BABA was effective against the zygomycete Rhizopus stolonifer in peaches.…”

“…BABA application also induced resistance against deuteromycota and zygomycota Aghdam et al, 2020). BABA application, for example, induced resistance against Aspergillus flavus in harvested pistachio fruits, reducing the fungal aflatoxin accumulation in kernels as well.…”