Evaluation of physicochemical characteristics of microwave vacuum dried mackerel and inhibition of oxidation by essential oils

Abstract

In the present study, Indian mackerel was dried by microwave vacuum drying (MVD) method and compared its physico chemical quality to mackerel dried by hot air drying (HAD) method. Antioxidant effects of thyme oil (TMO) and clove leaf oils (CLO) during storage were also evaluated. Brine salted mackerel was dried in hot air oven (50-55°C) and microwave vacuum dryer (600 W and 600 Hg mm). For essential oil treatment, mackerel was dipped in 0.75% TMO and CLO for 5 min. Moisture content of MVD and HAD samples was reduced to 30-32% in 1.2 h and 12 h, respectively. Rehydration ability and water absorption index of MVD samples were significantly higher to that of HAD samples. Mackerel dried by HAD showed significantly higher salt soluble and water soluble protein nitrogen fractions than that of MVD samples. Significantly higher hardness and chewiness values were observed for HAD samples. Color and appearance of uncooked MVD sample was superior to that of HAD samples. As per the results of PV and TBARS, TMO exhibited better antioxidant effect compared to CLO. The study demonstrated that fast drying can be achieved by microwave vacuum dryer and it can produce dried fish having better sensory and textural attributes.

Effect of ultrasound treatment on dehydration kinetics and physicochemical, microbiological, structural and rehydration characteristics of tilapia

“…Increased level of moisture absorption during the beginning of soaking period is attributed to surface adsorption and capillary action (Seremet, Botez, Nistor, Andronoiu, & Mocanu, 2016), while the reduction after is attributed to the drop in driving force required for moisture uptake when the rehydration progresses and approaches the equilibrium (Moreira, Chenlo, Chaguri, & Fernandes, 2008). Observations similar to those obtained in this study were reported in the previous studies for squid fillets subjected to hot air drying, freezedrying and heat pump drying (Deng et al, 2014), squid fillets by infrared radiation assisted heat pump drying (Wang et al, 2016), salted cod dried at low-temperature assisted by high power ultrasound (Ozuna, Cárcel, Walde, & Garcia-Perez, 2014), and microwave vacuum-dried mackerel (Viji et al, 2019).…”

Ultrasound use as a pretreatment for shrimp (Litopenaeusvannamei) dehydration and its effect on physicochemical, microbiological, structural, and rehydration properties

“…As expected, the absorbed water increased in all treatments and temperatures as the rehydration time also was longer, until reaching the saturation level (Figure 3) (Moreira et al, 2008). Similar rehydration behaviors were present in mackerel (Viji et al., 2019) and squid fillets (Wang et al., 2016) subjected to dehydration for different methods. Besides, the rehydration time was reduced by 16.7% and 12.5% for US15 and US30 at 30°C, respectively, and by 16.7% and 9.1% at 40°C, respectively, in comparison with the control treatments.…”

Physicochemical, microstructural, and microbial qualities of dehydrated Tuna chunks: Effects of microwave power and drying methods

“…There are only a few reports on the application of microwave vacuum drying for the dehydration of fish and fish products (Darvishi et al., 2013; Fu et al., 2015; Hu et al., 2013). In our previous studies, (Pankyamma et al., 2019; Viji et al., 2019), physicochemical and sensorial qualities of microwave vacuum‐dried products were found surpassing to those produced by conventional drying methods.…”

“…The vacuum was maintained at 700 mmHg (93.3 kPa) during all operations. The microwave power and vacuum used in the present study were decided based on our previous experiments (Pankyamma et al., 2019; Viji et al., 2019). Batch No.…”