Elucidation of techno-functional, structural and rheological characteristics of pectin extracted from the peel of different banana (Musa. spp) varieties.

Pectin is a polysaccharide mainly used in food processing industries as an emulsifier, thickener, stabilizer and in pharmaceuticals as an excipient, wall material and bio adhesive for improving delivery and efficiency. Raising demand for pectin, pushes to explore unconventional plant-based sources for the extraction of pectin. This work is aimed to explore the possibility of extracting pectin from the peel of banana varieties and to decipher the chemical and techno-functional properties. Among the varieties, Nendran, a plantain banana recorded higher pectin recovery (23.42 %), swelling power (23.10 gg-1), anhydrouronic acid (AUA) content (72.86 %) and emulsifying activity (46.19 %). Pectin from the banana peels exhibited the equivalent weight (g/mol) ranging from 943.40 (var. Bhimkol) to 1282.05 (var. Nendran). Morphological observations revealed that the extracted pectin has fragments with uneven sizes and inter-particle voids in the structure. Banana pectin behaved similar to commercial pectin in terms of rheological, textural and structural profiles. HPLC analysis and NMR spectra confirmed the dominance of galacturonic acid in the banana peel pectins. The study unveiled and opened up the avenues of utilizing banana peel as a complementary biomass for the extraction of pectin which could be used in different industrial applications.

Influence of chemical modifications on dynamic rheological behaviour, thermal techno-functionalities, morpho-structural characteristics and prebiotic activity of banana starches.

Banana starch is explored for its use in food and pharmaceutical applications. In this study, in order to improve the techno-functional properties of native banana starch (NS), different chemical modifications namely acid thinning (AT), oxidation (OX), sodium-trimetaphosphate method (STMP), cross linking phosphorylation (CLP), hydroxypropylation (HYP) were employed. Among the modified starches, amylose content was higher in CLP starch and the least was observed in AT. Resistant starch (RS) of HYP (65.38 %) and CLP starches (62.76 %) were significantly higher than other modified starches. Lesser amylose, higher water solubility and lower swelling of AT starch resulted in inferior paste clarity and inability to make a firm gel. Non-Newtonian behaviour of starch gels were observed from static viscosity observations. The dynamic rheological behaviour of the starch gels affirmed the higher gel strength of STMP (0.46) and CLP (0.56) starches. Imperfection and exo-corrosion in starch morphology was observed through SEM and influence of chemicals on the starch structure was elucidated through FTIR and XRD analyses. Except AT starch, modified starches with higher RS resulted in lowering glycemic index (57-69 %). STMP starches recorded highest prebiotic activity score of 0.88. Chemical modifications enable to enhance the functionalities of banana starch and offers potential industrial uses.

Effect of cellulose and gum derivatives on physicochemical, microstructural and prebiotic properties of foam-mat dried red banana powder.

Fruit sugars are gaining attention for their nutraceutical benefits. High sugar in ripe and over-ripe bananas makes them difficult for convective drying. In this study, red banana (RB) pulp was added with different gum derivatives as foaming agent (FA) (4 % w/w) viz., acacia gum(GA), carrageenan (CG) and gelatine(GE). Maltodextrin and carboxymethyl-cellulose were added as foam-stabilizers (FS). FA addition resulted in low density foam (RBGE-50 % reduction) with improved foam stability (RBGA-94.42 %). Powders were low in hygroscopicity (RBGA-18.62 g 100 g -1) with optimum flowability. The particle size (54.95 to 69.86 µm) of RB powder increased with gum derivatives addition. Secondary metabolites varied significantly in powder samples. Positive correlation of secondary metabolites with DPPH assay was observed. RBGA showed higher prebiotic activity (0.68) and supported the growth of tested Lactobacillus strain. Therefore, foam-mat dried RB powder with GA could be used in food formulation as low-cost alternative fruit sugar with higher nutritional, functional and prebiotic properties.

Influence of food hydrocolloids on the structural, textural and chemical characteristics of low-fat banana chips.

Banana chips are gaining popularity as a deep-fried product for its unique taste and flavour. This study is aimed to investigate the effect of hydrocolloids on oil absorption, physico-chemical and sensory properties of banana chips from two different varieties (var. Popoulu and var. Nendran), when fried at 180 °C for 3 min. The reduction in oil content was about 15%-35% and 19%-30% for hydrocolloid treated Popoulu and Nendran chips, respectively. The Free fatty acid content (FFA) of hydrocolloid treated banana chips was lower than that of untreated chips. The peroxide value (PV) values of all samples fell below 2 meq oxygen kg-1. CMC pre-treated banana chips were crispier than other formulations on both the varieties. Microscopic analysis showed the improved cellular integrity without large void spaces in hydrocolloid treated banana chips. PCA analyses elucidated that variables such as physical appearance, colour, crispiness, after taste, overall acceptability contributed positively, whereas hardness and sogginess contributed negatively to the correlation among the variables. From the chemical and sensory attributes, 0.5% CMC treated Popoulu chips and 1% CMC treated Nendran chips is recommended to produce chips with lower oil content.

Exploring differences in the physicochemical, functional, structural, and pasting properties of banana starches from dessert, cooking, and plantain cultivars (Musa spp.).

Banana starch, with its nutritional and functional properties, opens up new opportunities for the food industry, which is seeking new starch sources to fulfil rising demand. Herein, physico-chemical, and functional properties of banana starches isolated from dessert, plantain, and cooking cultivars were investigated. Starch yield was higher in Popoulu (30.58%) and Monthan (27.82%). Starch granules registered irregular forms with granule sizes ranging from 8.9 to 55.09 µm. Among the cultivars, the amylose content was ranged between 25.05 and 31.86%. Total starch (95.86 and 95.60%,) and resistant starch (65.56 and 59.20%) were higher in Saba and Monthan respectively. Flour colour index (86.2-90.6) was higher in banana starches. Differential scanning calorimetry and rapid viscosity studies confirmed that starches from Saba (87.67 and 85.71 °C) Monthan (85.36 and 81.65 °C) have a higher gelatinization property. Banana starches were B and C-type with varying crystallinity levels (21.19-52.01%). The in-vitro starch digestibility revealed that Saba starch has a lower hydrolysis rate with lesser glycemic index. PCA showed the greater impact of amylose and resistant starch content on the grouping of varieties. These findings would be useful for food and non-food industries in terms of using banana starch in various food compositions and other industrial applications.