Modelling the effect of temperature and water activity on the growth rate of Aspergillus flavus and aflatoxin production in peanut meal extract agar

Norlia M 1 , Jinap S 2 , Nor-Khaizura MAR 3 , Radu S 4 , John JM 3 , Rahman MAH 3 Show all authors , Peter ML 5 , Sharif Z 6

Affiliations 

  • 1 Faculty of Food Science and Technology, Universiti Putra Malaysia, 43400 Serdang, Selangor, Malaysia; Food Technology Division, School of Industrial Technology, Universiti Sains Malaysia, 11800 Minden, Pulau Pinang, Malaysia
  • 2 Faculty of Food Science and Technology, Universiti Putra Malaysia, 43400 Serdang, Selangor, Malaysia; Food Safety and Food Integrity, Institute of Tropical Agriculture and Food Security, Universiti Putra Malaysia, 43400 Serdang, Selangor, Malaysia. Electronic address: jinap@upm.edu.my
  • 3 Faculty of Food Science and Technology, Universiti Putra Malaysia, 43400 Serdang, Selangor, Malaysia
  • 4 Faculty of Food Science and Technology, Universiti Putra Malaysia, 43400 Serdang, Selangor, Malaysia; Food Safety and Food Integrity, Institute of Tropical Agriculture and Food Security, Universiti Putra Malaysia, 43400 Serdang, Selangor, Malaysia
  • 5 Food Safety and Food Integrity, Institute of Tropical Agriculture and Food Security, Universiti Putra Malaysia, 43400 Serdang, Selangor, Malaysia; Department of Food Science and Technology, Faculty of Engineering, University of Maiduguri, Borno State, Nigeria
  • 6 Food Safety and Quality Division, Ministry of Health Malaysia, Presint 3, 62675 Wilayah Persekutuan Putrajaya, Malaysia
Int J Food Microbiol, 2020 Dec 16;335:108836.
PMID: 33065380 DOI: 10.1016/j.ijfoodmicro.2020.108836

Abstract

Aspergillus flavus is the predominant species that produce aflatoxins in stored peanuts under favourable conditions. This study aimed to describe the growth and aflatoxin production by two A. flavus strains isolated from imported raw peanuts and to model the effects of temperature and aw on their colony growth rate as a function of temperature and aw in Peanut Meal Extract Agar (PMEA). A full factorial design with seven aw levels (0.85-0.98 aw) and five temperature levels (20-40 °C) was used to investigate the growth and aflatoxin production. Colony diameter was measured daily for 28 days while AFB1 and total aflatoxin were determined on day 3, 7, 14, and 21. The maximum colony growth rate, μmax (mm/day) was estimated by using the primary model of Baranyi, and the μmax was then fitted to the secondary model; second-order polynomial and linear Arrhenius-Davey to describe the colony growth rate as a function of temperature and aw. The results indicated that both strains failed to grow at temperature of 20 °C with aw <0.94 and aw of 0.85 for all temperatures except 30 °C. The highest growth rate was observed at 30 °C, with 0.98 aw for both strains. The analysis of variance showed a significant effect of strain, temperature, and aw on the fungal growth and aflatoxin production (p 

* Title and MeSH Headings from MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

MeSH terms
Similar publications