Waxy and non-waxy rice starches from japonica type Korean rice varieties were esterified with different levels of octenyl succinic anhydride (OSA), and the molecular structure of amylopectin (AP), ...digestibility, and emulsion stability were investigated. As OSA levels increased, the degree of substitution, granule size, peak and final viscosities, emulsion stability, and short chain of AP increased. However, the gelatinization temperature and enthalpy, and digestibility decreased. All OSA esterified starches showed a new band at 1723 cm
, but maintained A-type crystallinity. The DP6-12 of AP in waxy rice starch (WRS) was higher than that in non-waxy rice starch (NRS) with increasing OSA levels. Because the amylose and long chain of AP accessed easily with OSA groups, the digestibility of NRS was lower than that of WRS. The emulsion stability was higher in WRS than in NRS. From the above results, it is suggested that amylose should have a higher affinity with OSA esterification than AP and that the emulsion stability should increase in WRS, but the digestibility should decrease in NRS after OSA modification.
The particle size distributions (PSD) of rice flour and milling processes are important in making gluten-free products. The dry rice flour was prepared by grinding dried rice grains after soaking. ...Effects of PSD on the quality of rice cupcakes were investigated using the newly-developed rice flour. The flour properties passed through 80, 120, 160, and 200 (<180, <125, <95, and <75 μm) meshsieves, and batters and cupcakes prepared from their flours were analyzed. The PSD patterns showed two peaks containing cells and free starch fractions, in which the starch fraction peak intensity increased as a particle size decreased. While damaged starch, water binding capacity, solubility and lightness increased, crude protein and yellowness decreased as a particle size decreased. The final and setback viscosities increased as a particle size decreased. The specific volume of cupcakes was the highest in the cupcakes made with rice flour passed through under 95 μm. Hardness and springiness decreased as a particle size decreased. The air cell sizes decreased as a particle size decreased with homogeneity. Air cell homogeneity, volume, hardness, and softness of cakes determined by the different test, and appearance, texture, and overall quality determined by the preference test were all significantly different (p < 0.05).
•Particle size distributions of rice flours affect the type of gluten-free bakery products.•Rice flour passed through 120–160 mesh sieves (<125 μm) is appropriate for making rice cakes.•High swelling power, peak and setback viscosities of rice flour are important factors.
The aim of this study was to prepare starch-based filled hydrogels fortified with a model lipophilic nutraceutical (β-carotene) and determine the influence of starch type (mung bean or rice starch) ...and surfactant type (whey protein isolate (WPI) or Tween 20 (T20)) on lipid digestibility and β-carotene bioaccessibility. Microstructure, lipid digestion, and β-carotene bioaccessibility were measured as the emulsions and filled hydrogels were passed through a simulated gastrointestinal tract that included oral, gastric, and intestinal phases. The bioaccessibility was defined as the fraction of β-carotene solubilized within the mixed micelle phase after lipid digestion. Non-encapsulated T20-stabilized emulsions had better aggregation stability than WPI-stabilized emulsions under simulated gastrointestinal conditions, which led to a higher β-carotene bioaccessibility. Both Tween 20- and WPI-stabilized emulsions incorporated in starch-based filled hydrogels led to high lipid digestion and β-carotene bioaccessibility. The release behavior of free fatty acids during lipase digestion depended on the type of starch used as a hydrogel matrix, which was attributed to differences in starch structure. The information obtained in this study may be useful for the fortification of starch-based gelled products with lipophilic nutraceuticals.
Schematic diagram of filled hydrogel particles consisting of nutraceutical loaded lipid droplets incorporated within starch based hydrogels. Display omitted
•Lipophilic nutraceuticals (β-carotene) were trapped in lipid droplets.•Fortified filled hydrogels were fabricated by mixing lipid droplets and starch gels.•The rate of lipid digestion depended on emulsifier and starch type.•Nutraceutical bioavailability also depended on emulsifier and starch type.•Filled hydrogels may be formulated to alter the gastrointestinal fate of lipids.
•Starch nanoparticles were prepared from acid hydrolysis of waxy rice starch.•Crosslinking improved particle size distribution and RS level of nanoparticles.•Freeze-drying after sonication was good ...for drying of RS nanoparticles.•RS nanoparticles played the role of dietary fibre in a stable colloidal system.
To develop resistant starch (RS) nanoparticles, waxy rice starch was hydrolyzed with acid for 10 days, and acid-hydrolyzed waxy rice starch (AHW) was cross-linked with sodium trimetaphosphate. The RS nanoparticles were collected by freeze-drying (FD), freeze-drying after sonication (SFD), and ethanol dehydration after sonication (SE). The particle size distribution, RS level by modified AOAC, zeta potential, and stability of dispersion were assessed. The hydrolysis rate ranged from 44.62% to 49.43%, and AHW particle size decreased as hydrolysis time increased. All AHW and RS nanoparticles showed A type crystallinity. The particle size and zeta potential of the nanoparticles dried by FD, SFD, and SE were 300.0, 211.9, and 459.7 nm and −37.1, −43.0, and −35.4 mV, respectively. The RS levels were increased by cross-linking. The SFD dispersion was the most stable. The results indicate that the RS4 nanoparticles, for applying to liquid foods, can be prepared by acid hydrolysis, cross-linking, and SFD.
The purpose of this study was to apply a powdered β-carotene-loaded emulsion to a real food product, Korean traditional rice cakes (
Garaedduk
). β-Carotene was incorporated into the oil phase of a ...sodium caseinate-stabilized emulsion. Emulsion powder containing β-carotene was prepared using freeze-drying, and maltodextrin and gum arabic were used as wall materials. Oil/protein/maltodextrin weight ratios of 3:1:2 and 3:1:5 (core-to-wall ratios of 1:1 and 1:2) were used, and gum arabic was added by replacing the amount of maltodextrin for 0.1%, 0.2%, and 0.5% w/w. Manufactured emulsion powders prepared with wall material at a core-to-wall ratio of 1:2 remained stable after reconstitution in terms of particle diameter and ζ-potential. The encapsulation efficiency of the emulsion powder increased by 90% in the presence of maltodextrin at a core-to-wall ratio of 1:2.
Garaedduk
containing the emulsion powder was then manufactured and it was confirmed that β-carotene was not degraded during the manufacturing process of
Garaedduk
by using HPLC. The results from this study may be useful for rational designing of functional foods with lipophilic bioactive materials.
Dispersion of rice protein (RP) at a neutral pH is highly important for its application in the food industry. We analyzed the solubility of RP at different pH conditions and found higher solubility ...at pH < 3 and pH > 8 than at a neutral pH. Furthermore, at pH 2, the RP solubility improved from 30 to 63% with sonication; however, the samples precipitated when the pH was increased from 2 to 7. To circumvent this, anionic pectin and sodium alginate were added to the RP solution at pH 2. Pectin formed a complex with RP at pH 2, showing a shift in the zeta-potential from 17.3 mV (RP only) to − 1.0 mV (RP plus 1% pectin). Interestingly, the formation of this RP-pectin complex allowed RP to remain dispersed when the pH was increased to 7. Moreover, a stable emulsion could be prepared using the RP-pectin complex as an emulsifier.
In this study, the rice protein (RP) fractions (albumin, globulin, glutelin, and prolamin) in rice bran were obtained through the sequential extraction method using 2% (w/w) NaCl, 0.1 N NaOH, and 70% ...(w/w) ethanol and the proportions of water-soluble protein fractions (albumin) were compared among different degrees of milling (DM; 3%, 5%, 7%). The three types of bran showed different chemical components and populations of the four RP fractions. The 7% DM of brown rice is the stage at which the bran layers are completely removed and white rice is produced. In the 7%-DM bran, the content of water-soluble albumin was the highest
.
The extracted RP fractions contained eight essential amino acids and among them, albumin had the highest content of lysine. The secondary structures measured by circular dichroism spectroscopy were rich in alpha-helices. These results provide basic data for the extraction and utilization of water-soluble proteins from rice bran.
•Rice starch with modification of octenyl succinic anhydride (OSA) could be apply as a wall material.•Partial waxy rice, Baegjinju starch, was modified using different levels of OSA.•Increasing OSA ...level increased resistant starch content and emulsion stability.•Paprika carotenoids and OSA starch were sonicated and freeze-dried for encapsulation.•Encapsulated paprika pigment particle had high stability from processing conditions.
Physicochemical properties and emulsion stability of octenyl succinic anhydride (OSA)-modified partial waxy rice Baegjinju starches which were made with different OSA additions and the color stability of the encapsulated paprika pigment powder using the OSA starch were investigated. The DSs of the OSA starches ranged from 0.0152 to 0.0269. The band at 3303 cm−1 reduced as the OSA levels increased, but the A-type crystallinity was maintained. The oil absorption and emulsion stability, the short chain (DP6-12) amylopectin, the resistant starch levels, and the peak and final viscosities increased as the OSA levels increased. The encapsulated pigment powder with freeze-drying had higher color stability and better emulsion, and heating stabilities occurred with spray drying and the native pigment. From these results, it is suggested that the OSA-modified Baegjinju rice starch is a good wall material to protect lipophilic carotenoids. The encapsulated pigment powders could be used as stable natural colorants.
The starch structures and digestibility of starches prepared from newly developed Korean high amylose rice varieties were investigated. Amylose (AM) contents of Goami, Shingil, Goami 2, and Dodam ...starches were 25.56, 30.34, 36.33, and 45.78%, respectively. The Goami and Shingil starches were A-type crystallinity, while the Goami 2 and Dodam starches were B-type crystallinity. The molecular weights of AM were lower in the B-type starches (1.64 × 105 and 1.88 × 105) than in the A-type starches (3.88 × 105 and 3.00 × 105). The average chain length (CL) and longer branch CL (DP ≥ 25) of amylopectin (AP) were higher in B-type rice starches than in A-type rice starches. The ratio of 1045/1022 cm-1 and relative crystallinity were lower in the B-type rice starches. These results show that B-type starches have a higher AM content (>35%), gelatinization temperature, resistance to digestibility, and longer branch CL of AP, but a lower AM molecular weight than A-type starches.
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•High amylose Goami 2 and Dodamssal rice starches exhibited B-type crystallinity.•Gelatinization temperature was higher B-type starches than A-type starches.•Molecular weights of amylose were lower in B-type rice starches.•Long branched chain lengths (DP ≥ 25) of amylopectin were higher in B-type starches.•The digestibility was lower but resistant starch was higher in B type starches.
The emulsifying properties of rice proteins isolated from various non-waxy and waxy rice cultivars were studied to evaluate their potential application as oil-in-water (O/W) emulsifier and to compare ...the emulsifying properties of the rice proteins isolated from various rice cultivars. The solubility of the rice proteins was measured at different pHs (2–10), and O/W emulsions were prepared with the proteins at pH 2, 7, and 10. The rice protein-stabilized O/W emulsions were analyzed by measurement of particle size and zeta-potential, and observation under an optical microscope. The results indicated the potential of the rice proteins as emulsifiers at low and high pH values, and that, in particular, rice proteins isolated from waxy-rice cultivars could form stable emulsions even at neutral pH. The information obtained in this study may be useful for development of emulsion-based food products using rice protein isolate.
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