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Natural gums, which have a polysaccharide backbone, are widely used in the food processing industry as binders, thickeners and texturizing agents. Although all are hydrocolloids and physico-chemical properties of various gums have been described by various workers, there appears to be lack of detailed studies on their functional properties, which show appreciable differences. The present study was carried out to determine the key functional characteristics of commercially important natural gums. These included flow, solubility, water holding capacity and oil holding capacity, angle of repose, bulk and true density, and coefficient of friction. The bulk density of various gums ranged from 0.95-1.20 g/mL, the lowest densities was that of Babool gum and the highest was of Piyar gum. The compressibility index of various gums ranged from 1 to 38.75%. Khair gum showed the highest solubility (83.65%) and Karaya gum showed the lowest solubility (60.06%). Psyllium gum showed the highest water holding capacity whereas gum Acacia showed the lowest value. Oil holding capacity of different gums varied from 114.66 to 214.66 (g oil/100 g gum). Ghatti and Piyar gums (38.13°) showed comparative decrease in angle of repose, whereas Guar gum showed an angle of repose of 39.80°.

In this study, the gelation and thermal characteristics of microwave extracted fish scale gelatin blended with natural gums such as gum arabic (AG), xanthan gum (XG), guar gum (GG), and tragacanth gum (TG) was evaluated. The nature of interaction and behavior of gelatin in presence of various gums was confirmed by particle size analysis, viscosity profile, FT-IR analysis and turbidity measurements. DSC data revealed that addition of AG, TG and GG remarkably improved the thermal stability of fish gelatin gel. The composite gels of TG, AG, and XG exhibited higher hardness and bloom strength values as compared to pure fish gelatin implying its textural synergy. Based on qualitative descriptive analysis, TG was found to be superior in improving the stability of fish gelatin gel, closely followed by AG. The results suggest that addition of these gums can reduce syneresis and retard melting of gelatin gels at ambient temperature, which are otherwise soft and thermally unstable.

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The effect of edible coating using gum arabic on biochemical, microbiological, textural and sensory characteristics of fresh gutted mackerel stored at 4 °C was investigated. The results were further compared against the samples packed under vacuum (VP) and conventional polyethylene pouches (CP). Coating with gum arabic (GC) markedly retarded lipid oxidation process in gutted mackerel compared to VP and CP samples. Moreover, VP and CP samples showed higher degree of textural deterioration compared to GC samples. Microbiologically, the shelf life of chilled gutted Indian mackerel was estimated to be 7-8, 17 and 19-20 days for CP, GC and VP samples, respectively. The sensory analysis scores confirmed the efficacy of gum coating in retarding the spoilage process during chilled storage. The current study identifies the potential of edible coating with gum arabic to improve the overall quality of Indian mackerel and extend its storage life during chilled storage.