Application of immersion pre-treatments and drying temperatures to improve the comprehensive quality of pineapple (Ananas comosus) slices

Abstract

Drying of pineapple slices combined with different pre-treatments was done to reduce various adverse changes by adding satisfactory value. Process optimization was done by dipping the pineapple slices in four different solutions (1% trehalose, 2% NaCl, 10% sucrose, and 10% fructose) before drying. The effects of different pretreatments and drying temperatures of 50, 55, and 60 C with a constant 30% relative humidity (RH) were optimized based on the quality attributes, drying time and microbial load of dried pineapple slices. The optimal drying temperature was 55 C using 1% trehalose pre-treatments based on the physical and biochemical properties. The reconstituted dried pineapples implied at this condition, contributed to the better structure preservation as indicated by the lower shrinkage (0.21) and the higher Coefficient of Rehydration (0.941), and rehydration ratio (6.840). On the other hand, the retention of color, vitamin C, B vitamins, and antioxidant activity of the samples were decreased by increasing drying time and temperatures. The highest Total Phenolic Content (121.02 mg GAE/100g), Total Flavonoid Content (8.72 mg QE/100g), and DPPH radical scavenging activity (7.22 EC 50 g/100g) were found at 60 C drying temperature with 10% fructose pretreatment's samples. The lowest drying time required was 7.64 h using 2% NaCl pre-treatment at 60 C, considering the time required to reach 20% moisture content in the dried product at 30% RH. Based on the reported results, it is concluded that 1% trehalose at 50 C can be used to develop high quality pineapple snacks, which maintained the maximum desired physicochemical and nutritious properties. This study could play an essential role in meeting the emerging demand of developing good quality nutritious dried pineapple snacks.

Effect of osmotic pretreatment and drying temperature on drying kinetics, antioxidant activity, and overall quality of taikor (Garcinia pedunculata Roxb.) slices

“…( Mariani et al, 2008 ). However, factors such as temperature, relative humidity, air velocity, water diffusivity, load density, product shape, and thickness can affect the drying of food by hot air ( Hossain et al, 2021a , Zzaman et al, 2021 , Marchi et al, 2015 ). Therefore, the concept experimental drying technique using mathematical modeling is essential to decide the correct drying state to preserve taikor without degrading its consistency.…”

“…Osmotic pretreatment aimed to enhance the drying kinetics, retain the nutritional and physical quality of products, and preserve volatile compounds ( Sharma and Varma, 2014 ). Sugar and brine pretreatments reduce drying time and increase finished products’ storage capability ( Zzaman et al, 2021 , Roy et al, 2021 ). They inactivate enzymatic and non-enzymatic browning reactions, lower energy consumption, and preserve both color and fragrance.…”

“…10% sucrose, 10% fructose, and 2% sodium chloride (NaCl) were used. Based on prior studies, untreated and pretreated samples were then dried at three separate temperatures, for example, 45, 50, and 55 °C ( Önal et al, 2019 , Zzaman et al, 2021 ). It was expected that low temperature drying would help better retention of physicochemical and nutritional quality of Garcinia pedunculata.…”

Determination of Antioxidant Activity and Total Tannin from Drumstick (Moringa oleifera Lam.) Leaves Using Different Solvent Extraction Methods

“…Antioxidant molecules such as polyphenols can protect these reactive metals by scavenging them, which prevents further chain reactions responsible for chronic diseases in our body (Jomova et al, 2012). Fresh fruits and leafy vegetables containing natural antioxidants give protection to the body against free radicals when consumed (Zzaman et al, 2021;Sevindik et al, 2017). The consumption of antioxidant-rich fruits and vegetables has been found to lower the risks of many chronic and degenerative diseases (Ara et al, 2018).…”

Optimization of Antioxidant Extraction from Freeze-dried Pulp, Peel, and Seed of Burmese grape (Baccaurea ramiflora Lour.) by Response Surface Methodology

“…The total polar phenolic compound was determined by the modified Folin-ciocalteu reagent (FCR) method described by Zzaman et al (2021) with some moderations [22]. In a 10 mL flask, 0.5 mL of the ethanolic extract was placed.…”