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Introduction: Coconut testa, a by-product of the coconut processing industry, is currently underutilised. This study aimed to extract a coconut testa-based food colourant using various organic solvents and physical methods, and to utilise this colourant in food product preparation. Methods: Different organic solvents, along with various time and temperature combinations, were employed for colourant extraction using both a laboratory-scale water bath and ultrasonication. The colour coordinate values (CIELab) of the testa-derived colourants were measured, and the colourants were screened for various phytochemicals. The in vitro antioxidant potential of the testa colourant was assessed by quantifying total phenolics, and the phytochemical composition, including monomeric anthocyanins, was evaluated. Results: The study determined the optimal combinations of organic solvents, temperature and time to obtain extracts with maximum antioxidant activity and total phenolic content (TPC). Acidified ethanol-based extracts of testa colourants yielded highest polyphenol content (154.39 ± 2.63 mg GAE/g) and flavonoids content (53.65 ± 0.62 mg QE/g). Similarly, ethanol-based extractants of coconut testa produced high anthocyanin content [823.02 ± 1.81 mg Cy-3-glc equivalents (C3GE)/100 g]. Acidified (0.3 M HCl) solvents at relatively high temperature and time combinations exhibited high antioxidant potential of testa colourant, as measured by CUPRAC, FRAP, and DPPH assays. Following the foam mat drying process of the colourant, a mature coconut water-based jelly was prepared by incorporating the testa colourant extracted with acidified ethanol. Discussion: This study highlights the biochemical and antioxidant potential of the food colorant derived from coconut testa and explores its suitability for functional food applications. Therefore, coconut testa extract serves a dual purpose: it enhances the aesthetic appeal of food as a colourant and provides significant health-promoting properties due to its high anthocyanin content. Insights from this study could help in promoting the valorization of one of the beneficial by products of coconut industry. [ABSTRACT FROM AUTHOR]

The phloem sap tapped from unopened inflorescence (spadix) of coconut palm using a novel collecting device, "coco-sap chiller," has been branded Kalparasa® (henceforth as Kalparasa in the text) to distinguish its properties not found in sap harvested by traditional methods. To know its hitherto unidentified microbiome profile, we employed high-throughput sequencing to uncover the bacteriome and mycobiome in fresh and 12-h fermented samples. Fresh Kalparasa had a pH of 7.2, which dropped to 4.5 after 12 h, signifying fermentation of the sap. Diversity analysis indicated fresh Kalparasa having higher bacterial species than the fermented one. Contrary to this, fresh sap had lower fungal/yeast diversity than the fermented sample. Fresh Kalparasa had relatively higher abundance of probiotic-type Leuconostoc genus followed by equal proportions of Gluconobacter , Acetobacter , and Fructobacillus. The 12-h fermented Kalparasa showed a significant increase in Gluconobacter with a sharp decrease in Leuconostoc. Mycobiome data revealed fresh Kalparasa to be preponderant in Saccharomyces and Hanseniaspora genera of yeasts while the fermented sap had higher representation of Hanseniaspora and Cortinarius and lesser Saccharomyces. This suggested that the fermentation of Kalparasa was probably driven by symbiotic culture of bacteria and yeasts (SCOBY), particularly acetic acid bacteria and non- Saccharomyces yeasts. The bacteriome-function predictions highlighted the enrichment of glycerophospholipid, ABC transporters, purine, and pyrimidine metabolisms. Based on our findings, Kalparasa containing large population of Leuconostoc mesenteroides , Fructobacillus fructosus , Saccharomyces cerevisiae , and Hanseniaspora guilliermondii can be promoted as a healthy "unfermented" plant edible food containing live probiotic-type microbiome during its consumption. [ABSTRACT FROM AUTHOR]

Two plant growth promoting bacteria designated as KiSII and RNF 267 isolated from the rhizosphere of coconut palms were identified as Serratia marcescens and Enterobacter sp. based on their phenotypic features, BIOLOG studies and 16S rRNA gene sequence analysis. Both bacteria exhibited phosphate solubilization, ammonification, and production of indole acetic acid, β-1, 3 glucanase activities and 1-aminocyclopropane-1-carboxylate-deaminase activity. They could also tolerate a range of pH conditions, low temperature and salinity (NaCl). In addition, S. marcescens KiSII exhibited N- fixation potential, chitinase activity, siderophore production and antibiotics production. Seed bacterization with these bacteria increased the growth parameters of test plants such as paddy and cowpea over uninoculated control in green house assay. In coconut seedlings, significant increase in growth and nutrient uptake accompanied with higher populations of plant beneficial microorganisms in their rhizospheres were recorded on inoculation with both the PGPRs. The present study clearly revealed that PGPRs can aid in production of healthy and vigorous seedlings of coconut palm which are hardy perennial crops. They offer a scope to be developed into novel PGPR based bioinoculants for production of elite seedlings that can benefit the coconut farming community and the coconut based ecology. [ABSTRACT FROM AUTHOR]

Abstract: During vermicomposting of coconut leaves by the earthworm Eudrilus sp., Oryctes rhinoceros L. (rhinoceros beetle), an insect pest of palms, was found to breed in the decomposing organic material. Metarhizium anisopliae var. major was tried as a biocontrol agent for management of this pest. The effect of pathogen at spore loads of 103, 104 and 105 per 10g of substrate was tested in laboratory on Eudrilus sp. kept with O. rhinoceros grubs and on Eudrilus sp. alone for the pathogenic capability of the fungus on the pest and its possible toxicity towards the vermin. The efficacy of the entomopathogen was also tested in the field in vermicomposting tanks. In laboratory bioassay, 100% mycosis of O. rhinoceros grubs could be obtained while the entomopathogen had no toxic effect on the earthworms. There was a positive change in the number and weight of the earthworms on treatment with M. anisopliae. In the field, application of M. anisopliae reduced O. rhinoceros grubs in the vermicomposting tanks upto an extent of 72%. In conclusion, M. anisopliae could effectively control O. rhinoceros in vermicomposting sites and was non-hazardous to the vermicomposting process as well as the Eudrilus sp. [Copyright &y& Elsevier]