Thermal stability of natural pigments produced by Monascus purpureus in submerged fermentation

Abstract

Color is one of the most important characteristics of foods. It includes visual signals for flavor identification and taste thresholds. Furthermore, color plays significant roles in consumer satisfaction of foods (Hutchings, 2021). Legally permitted pigments are divided into two major categories of natural and synthetic.Natural colors include beneficial and therapeutic characteristics.Use of natural colors is one of the current marketing trends because of consumer's concerns about the safety of artificial food dyes, facilitated by possible health benefits of the natural pigments (Rodriguez-Amaya, 2016). However, natural pigments show more sensitivity and instability when exposed to environmental factors such as high temperature, oxidation, and pH than artificial

The potential, strategies, and challenges of Monascus pigment for food application

“…The (ii) submerged fermentation that are the microorganisms growing in a liquid medium with nutrients, which demonstrates the ease of homogenization and process control such as oxygenation, pH, and temperature (Agboyibor et al, 2019;Chai et al, 2020;Abdollahi et al, 2021;Abuthahir et al, 2021;Chen et al, 2021;de Almeida et al, 2021). In addition, the pigments are secreted into the fermentation medium and then recovered in a separation step, such as centrifugation or using simple solvent extraction (Lemes et al, 2021).…”

“…Once produced, pigments need to be properly obtained, separated, and identified, since their value and application are directly related to purity degree (Mukherjee and Singh, 2011) and stability, which can be affected by factors such as light, oxygen, and metal ions presence, pH levels, as well as high temperatures (Vendruscolo et al, 2016;Abdollahi et al, 2021). Separation methods vary according to the location of the pigment (intracellular or extracellular) production and the need for use for each application.…”

“…In this sense, the Monascus pigment has already had its stability evaluated under different conditions (Abdollahi et al, 2021;de Almeida et al, 2021), to allow its application and/or improvement of its stability to avoid changes in its properties (Vendruscolo et al, 2013;Xu et al, 2020a). Among the main limitations, related to its degradation, factors such as light, oxygen, metal ions, pH levels, and high temperatures are always highlighted (Agboyibor et al, 2018;Abdollahi et al, 2021), which vary according to the producing microorganism, way of obtaining, and method of extraction, among others.…”

“…Regarding pigment stability, it has also been reported that the stability is affected by different types of solvents during the extraction process, with an influence on yield, stability, and pigmentation capacity (Srianta et al, 2022). Furthermore, Monascus pigment does not completely lose pigmentation at temperatures up to 97.8 • C (Abdollahi et al, 2021;da Silva et al, 2022), pH in the range of 3 to 8 (da Silva et al, 2022), presence of several components, including salts (2, 5%) (Abdollahi et al, 2021) and solvents (Srianta et al, 2022), which corroborates and justifies its efficient application in different food matrices.…”

Uso de surfactantes como estratégia para melhorar o processamento do bagaço de cana-de-açúcar visando a produção de biopigmentos por >i<Monascus ruber>/i<

“…Kinetic models of pigment stability are also a useful tool to evaluate the pigment behavior when exposed to extreme conditions, thereby, assessing feasible solutions to enhance their stability (Liu et al, 2022). In fact, in a recent study, by applying a response surface methodology, the authors have observed higher stability of Monascus-derived pigments in lower temperatures (60ÚC -75ÚC) unless the pH was adjusted to 7 which enables the pigment stabilization in higher temperature range (75ÚC -88ÚC) (Abdollahi et al, 2021).…”