High internal phase Pickering emulsions stabilized by the complexes of ultrasound-treated pea protein isolate/mung bean starch for delivery of β-carotene

High internal phase Pickering emulsions (HIPPEs) stabilized by edible colloid particles have gained great interest. In this study, ultrasound-treated pea protein isolate and mung bean starch complexes (UPPI/MS) were prepared and used in stabilization of HIPPEs. The emulsifying properties of UPPI/MS were found to be superior to those of pea protein isolate (PPI), as evidenced by a smaller particle size and higher surface hydrophobicity. HIPPEs stabilized by UPPI/MS displayed a higher viscoelastic and gel-like structure. Low-Field NMR (LF-NMR) revealed that HIPPEs stabilized by UPPI60/MS (UPPI60/MS-HIPPEs) showed better ability to restrict the mobility of water. UPPI60/MS-HIPPEs also revealed the best environmental stability attributed a stronger three-dimensional network structure. Encapsulation of β-carotene within HIPPEs resulted in improving stability, with UPPI60/MS-HIPPEs exhibiting the highest retention rate of 73.58 %. Moreover, β-carotene encapsulated in HIPPEs displayed enhanced bioaccessibility, with UPPI60/MS-HIPPEs achieving the highest value of 25.37 %. This research highlighted the potential of UPPI60/MS complexes as effective stabilizers for HIPPEs and provided new insights on HIPPEs in nutrient delivery systems.

Amylopectin chain length distributions and amylose content are determinants of viscoelasticity and digestibility differences in mung bean starch and proso millet starch

This study aimed to reveal the underlying mechanisms of the differences in viscoelasticity and digestibility between mung bean starch (MBS) and proso millet starch (PMS) from the viewpoint of starch fine molecular structure. The contents of amylopectin B2 chains (14.94-15.09 %), amylopectin B3 chains (14.48-15.07 %) and amylose long chains (183.55-198.84) in MBS were significantly higher than PMS (10.45-10.76 %, 12.48-14.07 % and 70.59-88.03, respectively). MBS with higher amylose content (AC, 28.45-31.80 %) not only exhibited a lower weight-average molar mass (91,750.65-128,120.44 kDa) and R1047/1022 (1.1520-1.1904), but also was significantly lower than PMS in relative crystallinity (15.22-23.18 %, p < 0.05). MBS displayed a higher storage modulus (G') and loss modulus (G'') than PMS. Although only MBS-1 showed two distinct and discontinuous phases, MBS exhibited a higher resistant starch (RS) content than PMS (31.63-39.23 %), with MBS-3 having the highest RS content (56.15 %). Correlation analysis suggested that the amylopectin chain length distributions and AC played an important role in affecting the crystal structure, viscoelastic properties and in vitro starch digestibility of MBS and PMS. These results will provide a theoretical and scientific basis for the development of starch science and industrial production of low glycemic index starchy food.

Influences of high hydrostatic pressure on structures and properties of mung bean starch and quality of cationic starch

It is difficult to improve the quality of chemical-modified starch by traditional technology. Hence, in this study, mung bean starch with poor chemical activity was used as raw material, the native starch was treated and the cationic starch was prepared under high hydrostatic pressure (HHP) at 500 MPa and 40 °C. By studying the changes in the structure and properties of native starch after HHP treatment, the influence mechanism of HHP on improving the quality of cationic starch was analyzed. Results showed high pressure could make water and etherifying agent enter the starch granules through pores, and HHP made the structure of starch undergone three stages similar to mechanochemical effect. After HHP treated for 5 and 20 min, the degree of substitution, reaction efficiency and other qualities of cationic starch increased remarkably. Hence, proper HHP treatment could help to improve the chemical activity of starch and quality of cationic starch.

Characterization of acid hydrolysis based nano-converted mung bean (Vigna radiata L.) starch for morphological, rheological and thermal properties

Mung bean starch nanocrystals (SNC) were fabricated using acid hydrolysis. The resulting nanocrystals were studied for their morphological, thermal, and rheological properties. Irregular or round-shaped nano-scale crystals with average hydrodynamic diameter of 179 nm obtained after acid hydrolysis. The mung bean SNC revealed a C_B-type crystalline pattern with enhanced crystallinity as studied by X-ray diffraction (XRD). Lower negative zeta potential was obtained for mung bean SNC as compared to its native starch. Thermal peaks disappeared for nanocrystals, which indicated an increased thermal instability of mung bean SNC. A shear-thinning behavior, even at high concentrations of SNC in the suspension was noticed. The elastic behavior was observed at all studied concentrations and it was independent of the frequency change.

The multi-scale structure and physicochemical properties of mung bean starch modified by ultrasound combined with plasma treatment

Plasma is a simple, effective and promising food processing technology with great potential for starch modification. Mung bean starch was subjected to ultrasound (300 W, 10, 30 and 50 min), plasma (40 V, 1, 3 and 9 min) and the synergistic treatment, as well as investigating its effects on the morphology, chain length distribution, molecular weight, crystalline structure and physicochemical properties of starch. Ultrasound and plasma treatment did not change the granule shape, but caused some corrosions on the surface, and dual treatment increased the damage degree of starch granules surface. All treatments decreased the molecular weight (Mw), amylopectin long chains and crystallinity but increased the gelatinization temperatures and enthalpy. Different from ultrasound irradiation, single plasma treatment significantly reduced the swelling power and pasting viscosities. Furthermore, dual treatment increased the thermal stability of starch paste, owing to the reinforcement effect between ultrasound and plasma. Thus, dual modification displayed an excellent ability to modify starch with specific characteristics and expand the potential application of mung bean starch in the food industry.

Effects of microwave treatments and retrogradation on molecular crystalline structure and in vitro digestibility of debranched mung-bean starches

The objective of this study was to investigate morphology, molecular crystalline structure, and digestibility of debranched mung bean starches with or without microwave treatment and retrogradation at different temperature. The mung bean starch was firstly debranched with pullulanase, and then the debranched starch containing 20% moisture content was treated by microwave irradiation for 3 min with or without further retrograded at +25, +4, or -18 °C for 24 h. All treated starches exhibited the B + V-type crystalline polymorph as determined by the XRD and the ¹³CNMR. The FT-IR results showed that the debranched starches had lower degree of order but higher degree of double helix than those of the native starch. The microwave treatment or further recrystallization of the debranched starch for more 24 h significantly improved crystalline structure of starch granules with higher degree of relative crystallinity, degree of order, and degree of double helices. The resistant starch content of the treated starch was in a range of 39.7-52.8%, significantly higher than that of the native starch (15.6%). As a result, the microwave-assisted debranched starch with further crystallization for 24 h was found to have highly ordered structure of granules, which highly resisted to the enzyme digestion.

The multi-scale structure, thermal and digestion properties of mung bean starch

Identification and selection one special variety mung bean for lower GI food is very useful, however, the fundamental study for mung bean starch is still insufficient to meet its demand. In this study, four varieties of mostly planted mung bean in China were selected as model materials. The multi-scale structure of mung bean starch was characterized by SEC, HPAEC, XRD, SAXS, and SEM. SEC and HPAEC give the amylose contents, amylose and amylopectin fine structure of mung bean starch. Mung bean starch from XRD spectrum display C_A type semi crystallinity. The crystalline lamellar thickness from SAXS curves were 7.34-7.60 nm. DSC indicated that the peak gelatinization temperature is at 67 °C-68 °C. Resistant starch in mung bean disappears rapidly after cooking, although the amount of slowly digested starch was still more than half of the total starch. Since the gene backgrounds of the mung bean starch samples are very close, there was no obvious difference in their molecular and aggregated state structure, and the digestion properties were similar, too. Unique SEC and HPAEC profiles of starch chain length distribution can be utilized to help find more genetic resources and cultivate variety to meet the needs for starch applications.