Antioxidant and antimicrobial activities of hydrophilic extracts from shallot and garlic bulbs, and their effects on round scad during iced storage

Abstract

The present study aimed to investigate the in vitro antioxidant and antimicrobial activities of hydrophilic extracts prepared from shallot and garlic bulbs, and their effects on round scad during iced storage. Both the shallot and garlic extracts exhibited antioxidant activity concerning DPPH radical scavenging, total reducing power, and lipid peroxidation inhibition. The extracts also had antimicrobial activity against both Gram-positive (Bacillus cereus, Staphylococcus aureus) and Gramnegative (Escherichia coli, Salmonella typhimurium) pathogenic strains. Effects of treatment with the extracts on quality of round scad were evaluated by monitoring the total lipid hydroperoxides (HPO), thiobarbituric acid reactive substances (TBARS), total volatile basic nitrogen (TVB-N), total viable counts (TVC), and sensory characteristics. The spoilage indicators (HPO, TBARS, TVB-N, TVC) of the round scad treated with either shallot or garlic extracts were significantly suppressed during the ice storage period (P < 0.05). Round scad treated with either shallot or garlic extracts kept their natural sensory characteristics accepted for food-grade longer than 4 days of ice storage, compared with the control (without treatment). These results clearly show that the shallot and garlic extracts are potential natural preservatives, which can extend shelf-life of iced round scad.

Therapeutic Uses and Pharmacological Properties of Shallot (Allium ascalonicum): A Systematic Review

“…It was found that shallot extract exhibited good antioxidant activity concerning DPPH radical scavenging, total reducing power, and lipid peroxidation inhibition. Round scad treated with either shallot or garlic extracts kept their natural sensory characteristics accepted for food-grade longer than 4 days of ice storage, compared with the control (without treatment) ( Figure 2k ) ( 19 ). A recent study reported the development of active packaging film using sodium alginate and carboxymethyl cellulose along with shallot waste extract.…”

“…(k) Apparent changes occurred in round scad during ice storage. Shallot extract, the round scad was immersed in shallot extract; Garlic extract, the round scad was immersed in garlic extract; Control, the round scad was immersed in distilled water ( 19 , 46 ). (l) Anti-angiogenic effect of ethyl acetate fraction on CAM model of angiogenesis (arrows show neovascular forming in the chicken chorioallantoic membrane); (A) control, (B) treatment with EA fraction at 3 ng/egg, (C) treatment with ethyl acetate fraction at 10 ng/egg ( 47 ).…”

“…In a similar study, Duy Bao et al concluded that the aqueous extract of shallot can extend the shelf-life of round scad ( Decapterus maruadsi ) up to 4 weeks under ice storage conditions. They also revealed that this extract can inhibit the proliferation of several Gram-positive (i.e., Bacillus cereus, Staphylococcus aureus ) and Gram-negative (i.e., Escherichia coli, Salmonella typhimurium ) bacterial strains, however, with a lower inhibitory effect compared to garlic ( 19 ). Contrary to these results, Abdollahzadeh et al ( 52 ) revealed that the aqueous extract of shallot has no significant effect in extending the shelf-life of silver carp ( Hypophthalmichthys molitrix ) inoculated with L. monocytogenes PTCC 1163 strain at 4 ± 1°C.…”