Palm sap sugar an unconventional source of sugar exploration for bioactive compounds and its role on functional food development

Abstract

Palm sap sugar is a sweetener which is made from the sap or nectar collected from different varieties/species of palm trees. It has huge scope as an alternative sweetener in Indian market. It is a natural alternative to unhealthy cane sugar and is more beneficial for farmers as well. Some of its characteristic features are low GI value and its macro (Glucose: 0.49-86.90 g/100 ml, Fructose: 0.26-1.61, Sucrose: 5.30-27.00 g/100 ml) and micro (K: 65.28-1326.0, Na: 2.85-117.5, Mg: 0.54-31.00, Ca: 0.24-79.00 mg/100 ml) nutritional content. Palm sugar also has impact on colour, aroma and taste profile of the final product. The taste, sensory profile and nutritional attributes of palm sugar vary on the basis of its species, region of growth and climatic conditions. At present, traditional processing of palm sap leads to lower yield and higher expenses. There is huge potential in the field of development in processing techniques (Traditional processing, spray drying, membrane technology, and vacuum drying) to optimize the production of palm sugar. Palm sugar and other products from different parts of palm can be used to make a variety of other value-added products like toffees, chocolates, cola, toddy wine, candy, and palm vinegar etc. The purpose of this review paper is to summarise the composition of palm sap, distinctive qualities of the extracted sap, various production procedures, nutritional and physico-chemical properties of palm sugar, and the development of functional foods using palm sugar.

Keywords: Alternative sweetener; Health benefits; Phytochemicals; Tropical fruit.

Fig. 1

Palm sap composition (curated by the author).

Fig. 2

Parameters for palm sap quality (curated by the author).

Fig. 3

Spray drying technology for palm sugar preparation [25].

Fig. 4

Membrane technology for palm sugar preparation [26].

Fig. 5

Potential bioactive compounds present in palm sap, a) 2-propenoic acid; b) Dimethyl sulfoxide; c) Aromadendrin; d) Narcissoside; e) Procyanidin; f) Taxifolin; g) Luteolin 7-rutinoside; h) Tricin 7-glucoside; i) Peonidin 3-monoglucoside (curated by the authors themselves).