Influence of blanching treatment and drying methods on the drying characteristics and quality changes of dried sardine (Sardinella gibbosa) during storage

Abstract

The aim of this study was to examine the drying characteristics of blanched and unblanched sardine during indoor and open sun drying processes. Changes in temperature and relative humidity of the air during drying were recorded. The colour, peroxide value (PV), thiobarbituric acid reactive substances (TBARS), free fatty acid (FFA) content, fatty acid composition and sensory attributes of dried samples were also evaluated once a month for 5 months of storage. High drying rates were obtained in all samples at the start of drying and then decreased with increasing drying time. The highest drying rate and effective water diffusivity (D eff ) were observed in blanched sardine during open sun drying. Blanching treatment slowed down the FFA progression during products storage but adversely affected the colour, PV and TBARS content as well as sensory properties. Although sardine dried for a longer time under indoor drying conditions, it attained a stable moisture ratio that was lower than in open sun dried samples. Indoor drying produced a quality stable product with less lipid oxidation products and the desired moisture content, higher polyunsaturated fatty acids and sensory properties. Blanching Downloaded by [University of Birmingham] at 06:03 25 June 20162 treatment negatively affected the fish quality and is therefore not recommended for commercial sardine drying.

Impact of different drying processes on the lipid deterioration and color characteristics of Penaeus vannamei

“…also reported the effect of Maillard reaction on browning of fish. Furthermore, Cyprian et al . reported a relationship between the depth of sardine yellowness and the accumulation of lipid oxidation products such as hydroperoxides and aldehydes such as malondialdehydes, some of which could react with amines, amino acids and proteins to result in browning in many fatty foods during processing .…”

“…37 Kchaou et al 38 also reported the effect of Maillard reaction on browning of fish. Furthermore, Cyprian et al 39 reported a relationship between the depth of sardine yellowness and the accumulation of lipid oxidation products such as hydroperoxides and aldehydes such as malondialdehydes, some of which could react with amines, amino acids and proteins to result in browning in many fatty foods during processing. 40 Therefore, the lower degree of AST degradation, lipid oxidation and Maillard reactions for FD compared to HD can explain its better effect with respect to maintaining the color quality of dried shrimp.…”

Improvement of Pacific White Shrimp (Litopenaeus vannamei) Drying Characteristics and Quality Attributes by a Combination of Salting Pretreatment and Microwave

“…Pretreatment prior to drying is often utilized to accelerate the drying process, enhance product quality and reduce energy consumption. Several pretreatments have been employed to improve quality, reduce nutrient loss and extend the shelf life of dehydrated products, such as blanching [ 20 ], chemical treatment [ 21 ], ultrasound [ 22 ], high pressure [ 7 ], osmotic dehydration (OD) [ 23 ]. Li et al [ 24 ] found that ultrasound-assisted osmotic pretreatment significantly improved the quality of dried tilapia fillets with higher rehydration rates and Ca 2+ adenosine triphosphate synthase (Ca 2+ -ATPase) activity after heat pump drying.…”

Advances in the Formation and Control Methods of Undesirable Flavors in Fish

“…Meanwhile, Kim et al indicated that the fish gelatin of dried anchovies was hydrolyzed after boiling, forming an invisible edible film that protected against oxidative rancidity [ 126 ]. Boiling could slow the lipid hydrolysis process of dried sardines but adversely led to the loss of PUFAs, ultimately damaging sensory characteristics during storage [ 127 ].…”