Effects of Heating Temperatures and Acid Concentrations on Physicochemical Properties and Starch Digestibility of Citric Acid Esterified Tapioca Starches

Abstract

Physicochemical properties and starch digestibility of modified tapioca starch using various citric acid concentrations (10, 30, and 50 g/100 g dry starch) and heating temperatures (100, 120, and 140 °C for 5 h) are investigated. It is found that the degree of esterification increases with increasing dose of citric acid and heating temperature. Differential scanning calorimetry shows that citrate starch samples exposed to high acid dose (30 g/100 g citric acid) and temperature (120 °C) are resistant to gelatinization. In addition, transitional enthalpy also decreases with increasing concentration and temperature. The microstructure of esterified starch is observed to have agglomerated granules, with corrosions/fissures and small overlapping layers on the surfaces, which are observed in all modified samples. Citric acid esterification of tapioca starch provided advantages in terms of the increase resistant starch content and slow digestion rate when compared to native starch.

Effect of the Esterification of Starch with a Mixture of Carboxylic Acids from Yarrowia lipolitica Fermentation Broth on Its Selected Properties

“…The preparations with the highest DS were characterized by the lowest temperatures of the onset, end, and maximum of transition, and by the highest values of phase transition energy. This dependency was also confirmed in other works [ 24 , 25 , 28 , 39 , 40 ].…”

Production and Properties of Starch Citrates—Current Research

“…In recent studies, processes of esterification/crosslinking with citric acid have been conducted with various starch types, including both these produced on the large industrial scale, i.e., “normal” and waxy maize starch [ 27 , 31 , 32 , 33 , 34 , 35 , 36 ], wheat starch and its A and B fractions [ 22 , 37 ], potato starch [ 38 , 39 , 40 , 41 , 42 , 43 ], rice starch [ 44 , 45 ], and cassava starch [ 14 , 43 , 46 , 47 ], as well as with starch extracted from local plants, i.e., from banana [ 43 , 48 ], taro [ 49 ], yam [ 50 , 51 ], sweet potato [ 43 , 52 ], acha and iburu [ 53 ], kidney bean [ 54 ], lentil [ 43 ], and barley [ 16 ]. Investigations have been carried out with native starch (non-modified) and with starch modified using physical and chemical methods—porous starch [ 11 ], retrograded starch [ 41 , 42 ], starch nanocrystals [ 11 ], carboxymethyl starch [ 55 ], starch coated with nanoparticles [ 56 ], and alkaline starch suspension [ 57 ].…”

“…Different conditions producrf modified preparations with a substitution degree ranging from 0.01 to 0.42, which was found to depend on the type of starch material and its earlier modifications [ 37 , 41 , 42 , 43 ], citric-acid-to-starch ratio [ 11 , 37 , 38 , 39 , 41 , 42 , 43 , 46 , 47 , 52 , 58 ], pH value of the reaction [ 35 , 58 ], and the time and the temperature of roasting [ 35 , 42 , 47 ].…”

“…The changes observed on the surface of the esterified starch granules included corrosion and fissures. These changes were noticeable in modified preparations produced with the “wet” method [ 50 , 53 , 54 ], through roasting (the “dry” method) [ 37 , 38 , 43 , 44 , 47 , 51 , 60 ], with the electrochemical method [ 33 ], through microwave discharged cold plasma [ 36 ], and with the reactive extrusion method [ 34 ]. Their intensity was varied, and in extreme cases, it led to changes in starch granularity [ 33 , 49 , 58 ].…”

“…Thermal properties of starch esterified with citric acid differed from those of native starch obtained from various botanic sources ( Table 2 ). Several studies demonstrated a decrease of phase transition temperature and a decrease of phase transition heat of the citrates compared to native starch [ 38 , 42 , 44 , 46 , 47 , 49 , 50 , 54 ]. The modified preparations produced via the microwave-discharged cold plasma treatment, having a crystallization degree similar to that of native starch, exhibited similar phase transition temperatures and transition heat to native starch [ 36 ].…”