Nutritional profiling of coconut (Cocos nucifera L.) inflorescence sap collected using novel coco-sap chiller method and its value added products

Abstract

Coconut inflorescence sap is a phloem sap collected from the unopened coconut spadix. A new ‘coco-sap chiller method’ (CSCM) is developed to collect fresh and unfermented sap devoid of extraneous matter. A study was conducted to identify and compare the nutrients present in the sap collected by CSCM and the sap collected by traditional method (TM) using lime coated earthen pot, and also in the sap concentrate and coconut sugar prepared from sap collected by CSCM. Profiling of amino acids, phenolic acids, flavonoids and vitamins was also done using Ultra-Performance Liquid Chromatography/ Tandem Mass Spectrometry (UPLC coupled with TQD-MS/MS). Distinct variation in physical and biochemical properties were recorded between the sap collection methods. The sap collected by CSCM was slightly alkaline (pH 7–8), golden brown in color, sweet and delicious and rich in nutrients and zero alcoholic. While the sap collected by TM was acidic (pH below 6), oyster white in color and gave astringent smell and had about 2.32% alcohol. Sap collected by CSCM was rich in essential amino acids like lysine, threonine and histidine. A total number of thirteen phenolic acids and seven flavonoids were identified from coconut sap, sap concentrate and sap sugar. Vanilic acid, syringic acid, trans-cinnamic acid and p-hydroxy benzoic acid are the major phenolic acids and catechin, hesperitin, and myricetin are the major flavonoids identified. Vitamin C, niacin, and tocopherol are the major vitamin identified. Except few vitamins, all the nutrients present in the sap were preserved in the sap concentrate and coconut sugar. In summary, coconut sap collected by CSCM was fresh and contained numerous health promoting biochemical constituents such as phenolics, flavonoids and vitamins. Hence it can be consumed as ready to serve non-alcoholic health drink. Similarly, nutrient rich sap concentrate and coconut sugar can be prepared from fresh sap collected by CSCM without the addition of any chemicals.