Mito Kokawa

Liquid-core alginate hydrogel beads loaded with functional compounds of radish by-products by reverse spherification: Optimization by response surface methodology

Liquid-core hydrogel beads (LHB) were formulated through reverse spherification, by sodium alginate and using calcium lactate (CL) to replace the common calcium source, calcium chloride. The effect of four independent variables: first gelation time (X1), CL concentration in first gelation (X2), secondary gelation time (X3), and CL concentration in secondary gelation (X4), on seven physical properties of LHB: diameter, hardness (Y1), loading efficiency (LE, Y2), release amount of total phenolic compounds (TP) in simulated gastric (Y3) and small intestinal (Y4) fluid, swelling capacity (Y5), and sphericity (Y6), were evaluated. Furthermore, a central composite design with response surface methodology was used for the optimization of LHB properties Y1-Y6, and the importance of the four independent variables to physical properties was analyzed. The diameter of LHB was in the range of 4.17-5.84mm. The optimal conditions of LHB formulation were first gelation time of 23.99min, 0.13M CL in the first gelation, secondary gelation time of 6.04min, and 0.058M CL in secondary gelation. The optimized formulation of LHB demonstrated 25.5N of hardness, 85.67% of LE and 27.38% of TP release in simulated gastric fluid with the small error-values (-2.47 to 2.21%).

Simultaneous estimation of scavenging capacities of peach extract for multiple reactive oxygen species by fluorescence fingerprint method

In this study, the potential of using fluorescence fingerprint, also known as fluorescence excitation-emission matrix, for estimating the scavenging capacity of peach extract on reactive oxygen species (ROS) was investigated. Samples from each of the five cultivars (Asama Hakuto, Hakuho, Kawanakajima Hakuto, Natsukko and Ougonto) were freeze-dried and crushed. The scavenging capacities of peach extracts for the target ROS (hydroxyl, superoxide, alkoxyl radicals and singlet oxygen) were measured by electron paramagnetic resonance spin trapping method. Fluorescence fingerprints of the same samples were obtained. Partial least squares regression analysis was carried out to develop prediction models for ROS scavenging capacity. The models were assessed by external validation. Fluorescence fingerprint was found to accurately estimate the scavenging capacity for the alkoxyl and superoxide radicals with the prediction error of 0.06mmoltroloxeq./mL and 0.31mmolα-lipoicacideq./mL with a coefficient of determination of prediction (R2P) of 0.78 and 0.91, respectively.

Preparation and physical property assessments of liquid-core hydrogel beads loaded with burdock leaf extract

Secondary gelation is an important but overlooked element which has a significant impact on the quality of liquid-core hydrogel beads (LHB). This study firstly searches the optimized extraction conditions of burdock leaf and analyses its functional compounds and antioxidant abilities. Then, we measure loading efficiency, relative hardness, swelling capacity, and outer appearance to evaluate the optimized preparation conditions of LHB loaded with burdock leaf extract (BLE). The results showed that the optimized extraction conditions of burdock leaf were a solid to liquid (95% ethanol) ratio of 1u2006:u20063, and extraction at 80 °C for 90 min. This extraction contained 23.81 mg g−1 dw chlorogenic acids (CGA) and the DPPH scavenging activity was 59.49%. LHB prevented the DPPH scavenging ability of BLE from decreasing during storage. The diameter and swelling capacity of burdock LHB increased, and hardness and loading efficiency decreased with longer gelation times. Relative hardness of the LHB prepared by 1% CaCl2 in the secondary gelation was 5.6-fold higher than that of the control, but there was no significant difference in CGA loading efficiency.

Predicting the Heating Temperature of Soymilk Products Using Fluorescence Fingerprints

A novel measurement technique using fluorescence fingerprints (FFs) was developed to measure the degree of heat treatment applied to soymilk. FFs are a set of fluorescence spectra acquired at consecutive excitation wavelengths. Soymilk was heated at 50, 60, 70, 80, or 90xa0°C, for 10xa0min, and the samples were measured both in the liquid and freeze-dried forms. Partial least squares (PLS) regression models were constructed to predict heating temperature from the FFs of liquid soymilk and freeze-dried soymilk. Heating temperatures were predicted from soymilk FFs with root-mean-square errors of prediction (RMSEP) and R2P of 7.20xa0°C and 0.92 and from freeze-dried soymilk FFs with RMSEP and R2P of 9.00xa0°C and 0.89, respectively. The fluorescence of aromatic amino acids and Maillard products mainly contributed to the prediction models. FF measurement proved to be effective for the objective control of the soymilk heating process.

Effect of gum arabic-modified alginate on physicochemical properties, release kinetics, and storage stability of liquid-core hydrogel beads

Different weight ratios of alginate/gum arabic (GA) solutions were prepared to serve as the wall material of liquid-core hydrogel beads (LHB) that were formulated to protect the total phenolic compounds (TP) of radish by-product juice from degradation during storage and release in simulated gastrointestinal fluid. The diameter of LHB ranged from 4.63 to 5.66mm with a sphericity lower than 0.05. LHB formulated with 25% GA (AGB0.25) exhibited the highest hardness (26.63N), and those formulated with 50% GA (AGB0.50) exhibited the highest loading efficiency (86.67%). AGB0.25 was effective in preventing TP from degrading during storage with a decay rate (k) of 6.10×10-3day-1 and a half-life (t1/2) of 113.63 days, it showed the slowest release of TP in simulated gastric fluid (k=2.25×10-6), and the release mechanism followed Fickian diffusion. The results suggest that GA is effective in improving the physicochemical properties of alginate.

Degradation Kinetics and Storage Stability of Vacuum Spray-Dried Micro Wet-Milled Orange Juice (Citrus unshiu) Powder

The aim of this work was to evaluate the degradation kinetics and stability of micro wet milled orange juice powders obtained by vacuum spray drying, using maltodextrin as a carrier agent. Powders were produced with four combinations of orange juice solids/maltodextrin solids 60:40, 50:50, 40:60, and 30:70 by weight. Ascorbic acid degradation, color, and antioxidant activity of powders were evaluated throughout 90xa0days. Powders were stored at 10, 25, and 35xa0°C and relative humidity of 33%. Temperature and storage time negatively influenced the stability of ascorbic acid and color, whereas antioxidant activity increased at the beginning of storage at a higher temperature then decreased slightly after 60xa0days. For stability study, powders were stored at different water activities (0.11 to 0.84) in order to determine the plasticizing effects of water on glass transition temperature. Both water activity and glass transition temperature were used to predict the critical conditions for storage. Vacuum spray dried powder produced with a ratio of 30:70 (orange juice solids/maltodextrin solids) was considered as the most stable, since it showed highest critical water activity (awu2009=u20090.61) and lowest moisture content (0.11xa0g water/g of dry solid) among the four powders. Vacuum spray drying using superheated steam as the heating medium was proven to be an effective way of producing orange juice powders with minimum loss of nutrients.