Improvement of Sensorial, Physicochemical, Microbiological, Nutritional and Fatty Acid Attributes and Shelf Life Extension of Hot Smoked Half-Dried Pacific Saury (Cololabis saira)

Abstract

Half-dried Pacific saury of Cololabis saira (HDPS) is a fatty fish of high nutritional value with remarkable consumer interest in the Asia Pacific region, however, it undergoes various deteriorative changes associated with browning, bacterial contamination, oxidation, and decreased sensory attributes while marketed in various processed forms. To withstand these complications, research aimed to investigate the hot smoking technology to improve physicochemical, microbiological, and sensory attributes of HDPS with prolonged shelf life in storage conditions. The HDPS fillets were processed with hot smoking (70 °C) using various sawdust materials of Apple, Chestnut, Oak, Cherry, and Walnut, wherein the smoke time was set at different time points of 0, 20, 25, and 30 min. The results indicated that 25 min of smoking time with the selective Oak sawdust showed better sensorial characteristics, physicochemical properties, and microbiological qualities. Moreover, HDPS possessed higher nutritional value and valuable functional fatty acids, particularly docosahexaenoic acid and eicosapentaenoic acid, having a storage ability of up to 30 days at 10 °C. The processed HDPS offered a reduced level of Trimethylamine-N-oxide and Benzo[a]pyrene contents, indicating the acceptable and safe for human consumption. Therefore, HDPS with hot smoking could likely be a promising technique for preserving the premium quality of the product by providing desired characteristics of health and nutrition to end-point consumers.

Keywords: hot smoking of fish; microbiology and nutrition; physicochemical properties; sensory evaluation.

Figure 1

Use of different sawdust materials on the improvement of sensory attributes of (a) odor (a.u.) and (b) overall preference (hedonic score) at 20 and 25 min of hot smoking times of half-dried Pacific Saury (HDPS). Data represent the mean ± std of 10 observations, where groups not sharing a letter are expressed as significantly different (p < 0.05).

Figure 2

Different smoking times on the changes of (a) odor (a.u.) and (b) sensory quality attributes of hot smoked HDPS. Data represent the mean ± std of 10 observations, where groups not sharing a letter are expressed as significantly different (p < 0.05).

Figure 3

Different smoking times on the effects of (a) weight loss, (b) texture analysis, (c) odor (a.u.), and (d) color value of hot smoked HDPS. Data represent the mean ± std of 10 observations, where groups not sharing a letter are expressed as significantly different (p < 0.05).

Figure 4

Different smoking times on the improvement of (a) TBC (CFU/g), (b) pH, (c) TBARS, (d) VBN (mg%), and (e) sensory evaluation of hot smoked HDPS. Data represent the mean ± std of 10 observations, where groups not sharing a letter are expressed as significantly different (p < 0.05).

Figure 5

Consequences of storage time on (a) volatile basic nitrogen (VBN) and (b) sensory evaluation (overall preference) of hot smoked HDPS at two different storage temperature of 10 °C and 15 °C Data represent the mean ± std of 10 observations, where groups not sharing a letter is expressed as significantly different (p < 0.05).

Figure 6

The trimethyl N-oxide (TMAO) was identified and quantified by GC/MS analysis. The representative chromatograms of (a) standard TMAO, (b) raw HDPS, and (c) hot smoked HDPS. The TMAO was identified and quantified by the reference TMAO injecting into the GC/MS. The TMAO spikes in the chromatograms appeared at 1 min 25 s of retention time among different treatment groups.