Physico-chemical aspects of Thai fermented fish viscera, Tai-Pla, curry powder processed by hot air drying and hybrid microwave-infrared drying

Abstract

The objective of this research was to comparatively investigate the effect of hot air drying (HA) and hybrid microwave-infrared drying (MI) on physico-chemical characteristics of Thai fermented fish viscera, Tai-Pla, curry powder (TCP). HA was carried out at 60°C, 70°C, and 80°C and MI was carried out at a microwave power of 740, 780, and 810 W with a constant infrared heating power (500 W) for different drying times to obtain the final moisture content ≤ 12.0% and the water activity (aw) ≤ 0.6. The quality characteristics of TCP were governed by HA temperature and MI output power. TCP dried using HA and MI at all conditions had similar contents of protein, lipid, ash, fiber, and carbohydrate (p>0.05). The fastest drying rate was detected when MI at 810 W for 40 min was applied (p<0.05). In this condition, TCP had the lowest browning index (A294 and A420) and the highest lightness (L* value) (p<0.05). TCP dried with MI at all powers had higher phenolic content and lower TBARS compared to HA (p<0.05). However, no significant differences in DPPH• scavenging activity were observed among TPC made by HA and MI (p>0.05). Similar Fourier transform infrared (FTIR) spectra with different peak intensities were observed in all samples, indicating the same functional groups with different contents were found. The bulk density of all TCP ranged from 0.51 g/mL to 0.61 g/mL and the wettability ranged from 24.02% to 26.70%. MI at 810 W for 40 min effectively reduced the drying time (5-fold faster) and lowered the specific energy consumption (18-fold lower) compared to the HA at 60°C for 210 min. Therefore, MI is a promising drying technique to reduce the drying time and improve the overall quality of TCP.

Effect of antifungal compounds secreted by Lactiplantibacillus plantarum 124 against Aspergillus flavus and Penicillium sp. and its application in Kaeng‐Tai‐Pla‐Haeng to extend the shelf life

“…Choopan et al . (2021) reported that free amino acids and other soluble non‐nitrogenous substances derived from Tai‐Pla (fermented fish viscera) sauce and fermented shrimp paste, as sources of protein, could serve as nutrients supporting microorganism growth until 1 × 10 4 CFU g −1 sample.…”

“…Kaeng‐Tai‐Pla‐Haeng was prepared by the red curry paste mixed with shrimp paste and mackeral meat, then heated with water together with Tai pla sauce until it boiled and let the water evaporate until the water activity was approximately 0.85. (Choopan et al ., 2021), and then divided into four groups. A freeze‐dried supernatant of L. plantarum 124 at its MIC was supplemented in Kaeng‐Tai‐Pla‐Haeng , which was expected to inhibit fungal spoilage growth.…”

“…This means that the shelf life of Kaeng-Tai-Pla-Haeng supplemented with antifungal compounds was extended from 7 to 21 days compared to the control treatment. Choopan et al (2021) reported that free amino acids and other soluble nonnitrogenous substances derived from Tai-Pla (fermented fish viscera) sauce and fermented shrimp paste, as sources of protein, could serve as nutrients supporting microorganism growth until 1 9 10 4 CFU g À1 sample.…”

“…The main ingredients are fresh curry paste, grilled fish meat, and Tai‐Pla sauce (salty, fermented fish entrails). Kaeng‐tai‐pla‐haeng is cooked and processed by heating the mixture of all curry ingredients under continuous stirring until water activity ( A w ) has reached approximately 0.85 or lower (Choopan et al ., 2021). However, this product is highly susceptible to contamination by fungi of various genera, among which Penicillium and Aspergillus are the most commonly found fungi (Cheenkaew et al ., 2020).…”

“…The common methods of food preservation to control fungal spoilage in food products are based on the use of chemical additives and physical treatments (Schnürer & Magnusson, 2005). However, physical methods such as irradiation or thermal treatments often cause a loss in nutrition, and can change the sensory characteristics of the food (Choopan et al ., 2021). Meanwhile, chemical preservatives, such as sorbic acid, benzoic acid, and calcium propionate, are highly concerned regarding their negative impacts on human health at high concentrations (Adebayo & Aderiye, 2011).…”