Prebiotic Pectin from Mango Peel and Economic Feasibility Assessment

Abstract

Mango is a well-known tropical fruit consumed in both fresh and processed forms. Peel of mango, a major byproduct from the processing has been recognised as a potential source of food-grade mango peel pectin (MPP). This thesis investigated peels of four Thai mango varieties, viz., 'Mahachanok', 'Namdokmai', 'Chok anan' and 'Kaew' were for MPP production. The influence of fruit physical characteristics and phytochemicals of peels on MPP qualities was conducted. Thereafter, the MPP was hydrolysed and produced mango peel pectic oligosaccharide (MPOS) as prebiotic for lactic acid bacteria. Finally, the economic feasibility of MPP and MPOS production in the industrial scale were compared in order to give the guideline to food processors and to comply with the bio-circular green economic (BCG) model. res e rve The first study, mangoes of 'Mahachanok' and 'Namdokmai' were distinctive to 'Chok anan' and 'Kaew' on the basis of their physiology, and phytochemical characteristics. Only pectin extracted from mango var. 'Chok anan' was categorised as low methoxyl type (~ 4% of methoxyl content). The multivariate correlation between the fruit and peel properties and the degree of esterification (DE) value illustrated that the biomass volume such as yield of the seed and the total mass had negatively influenced the DE values, while they were positively correlated with the contents of crude fibre and xylose of the peels. In the hydrolysis, the optimal treatment for MPOS valorisation was 24 h with 0.3% (v/v) pectinase. This condition provided small oligosaccharides with the molecular weight of 643 dalton that demonstrated the highest score of prebiotic activity for both of Bifidobacterium animalis TISTR 2195 (7.76) and Lactobacillus reuteri DSM 1 7938 (6.87). The major sugar compositions of the oligosaccharide using HPLC analysis were fructose and glucose. For the simulation of prebiotic fermentation, B. animalis TISTR 2195 showed higher proliferation and short chain fatty acid production in 4% (w/v) of MPOS supplemented than that of L. reuteri DSM 1 7938. I then summarised that the MPOS is a novel pectic oligosaccharide resource. Finally, the profitability of MPP and MPOS processing was assessed based upon the net present value (NPV), internal rate of return (IRR) payback period (PBP) and the sensitivity analysis. MPOS was found to be the great alternative for mango peel valorisation with higher values of the NPV ($255.71 millions), IRR (57.42%) and lower PBP (1.74 years) than MPP. Sensitivity analysis described that plant capacity had the most influence on the accumulated capital. While the operation day showed the least effect and longer time provided the decrease of NPV. This valuable information also confirmed that the additional MPOS processing were cost-effective with good return on the investment capital. The outcome from this research would provide a profitable opportunity for the sustainable growth of the country through and also the baseline guidance of value adding ingredients from the biomass of Thai fruit industry.