Optimization of ultrasonic-assisted enzymatic extraction of kiwi starch and evaluation of its structural, physicochemical, and functional characteristics

Abstract

Graphical abstract

Modification in structural, physicochemical, functional, and in vitro digestive properties of kiwi starch by high-power ultrasound treatment

“…According to our previous study [7] , the DSC determination was recorded by a Q2000 DSC (TA Instruments, Norwalk, USA). The onset temperature (To), peak temperature (Tp), conclusion temperature (Tc), and enthalpy change (ΔH) were recorded.…”

“…The onset temperature (To), peak temperature (Tp), conclusion temperature (Tc), and enthalpy change (ΔH) were recorded. The pasting properties were measured by a Rapid Visco-Analyzer (RVA-Tec Master, Perten Instruments, Sweden) [7] . The time to peak viscosity (Ptime), pasting temperature (PT), peak viscosity (PV), hot paste viscosity (HPV), cold paste viscosity (CPV), breakdown value (BD), and setback value (SB) were measured.…”

“…Starch is the main dietary source of carbohydrates and the most abundant storage polysaccharide in plants, which exists in the amyloplast of plant fruits, pericarps, or seeds [1] . They can be obtained from a variety of plant sources such as cereals (wheat, corn, and rice) [2] , tuber crops (potato, cassava, and yam) [3] , legumes (bean and pea) [4] and green or immature fruits (banana, mango, and kiwifruit) [5] , [6] , [7] . Among them, raw kiwifruit, that is, during or before the commercial picking period is a new source of fruit-derived starch (40–60% on a dry basis) that has not been focused on [8] .…”

“…It has been verified that kiwi starch (KS) not only has similar features to traditional starch but also has the particularity of starch derived from fruits or vegetables. It has a low pH value, a large amount of dietary fiber and phenolic substances, and a high content of resistant starch (RS), which can be used as a novel and healthy food formula and may have a positive impact on the kiwi industry [7] , [8] , [9] , [10] . Nevertheless, native KS still has many shortcomings, such as low solubility in cold water, low clarity, low pseudoplasticity, and weak gel strength, which largely limits its application in food and non-food industries [7] , [8] , [9] , [10] .…”

“…It has a low pH value, a large amount of dietary fiber and phenolic substances, and a high content of resistant starch (RS), which can be used as a novel and healthy food formula and may have a positive impact on the kiwi industry [7] , [8] , [9] , [10] . Nevertheless, native KS still has many shortcomings, such as low solubility in cold water, low clarity, low pseudoplasticity, and weak gel strength, which largely limits its application in food and non-food industries [7] , [8] , [9] , [10] . In order to improve the performance of KS to meet the requirements of special processing unit operations and increase its added value, it is necessary to modify KS to enhance the positive attributes and minimize these drawbacks.…”