A R Silva1, A S Sant'Ana, P R Massaguer. 1. Department of Food Science, Faculty of Food Engineering (FEA), University of Campinas (UNICAMP), Campinas, SP - Brazil. marx@fea.unicamp.br
Abstract
AIMS: To assess the behaviour of Aspergillus section Nigri IOC 4573 in mango nectar as affected by temperature and pH. METHODS AND RESULTS: A central composite design (2(2)+2*2+3) was used to estimate the influence of temperature (17·2-22·8°C) and pH (3·28-4·7) on A. section Nigri growth (λ, lag time; μ, growth rate). Secondary models (polynomial and Arrhenius-Davey) describing the effects of temperature and pH on λ and μ were constructed. A decrease in temperature from 22·8°C to 17·2°C resulted in an a 16-fold increase in λ. The increase in temperature from 20°C to 22·8°C at pH=4·0 led to a fourfold increase in μ. The polynomial model was the best in fitting the data and the pH (linear), temperature (linear and quadratic terms) significantly influenced λ. For μ, there was a significant influence by the pH (linear), temperature and pH (quadratic terms). CONCLUSIONS: The storage of mango nectar at <15°C and reduced pH could completely inhibit the growth of A. section Nigri. SIGNIFICANCE AND IMPACT OF THE STUDY: This is the first study to show how storage temperature and seasonal variability (pH) between harvests may affect mould growth in mango nectar.
AIMS: To assess the behaviour of Aspergillus section Nigri IOC 4573 in mango nectar as affected by temperature and pH. METHODS AND RESULTS: A central composite design (2(2)+2*2+3) was used to estimate the influence of temperature (17·2-22·8°C) and pH (3·28-4·7) on A. section Nigri growth (λ, lag time; μ, growth rate). Secondary models (polynomial and Arrhenius-Davey) describing the effects of temperature and pH on λ and μ were constructed. A decrease in temperature from 22·8°C to 17·2°C resulted in an a 16-fold increase in λ. The increase in temperature from 20°C to 22·8°C at pH=4·0 led to a fourfold increase in μ. The polynomial model was the best in fitting the data and the pH (linear), temperature (linear and quadratic terms) significantly influenced λ. For μ, there was a significant influence by the pH (linear), temperature and pH (quadratic terms). CONCLUSIONS: The storage of mango nectar at <15°C and reduced pH could completely inhibit the growth of A. section Nigri. SIGNIFICANCE AND IMPACT OF THE STUDY: This is the first study to show how storage temperature and seasonal variability (pH) between harvests may affect mould growth in mango nectar.
Authors: Luísa Freire; Tatiane M Guerreiro; Arthur K R Pia; Estela O Lima; Diogo N Oliveira; Carlos F O R Melo; Rodrigo R Catharino; Anderson S Sant'Ana Journal: Sci Rep Date: 2018-10-01 Impact factor: 4.379