Enzymatic hydrolysis increases ginsenoside content in Korean red ginseng (Panax ginseng CA Meyer) and its biotransformation under hydrostatic pressure.

BACKGROUND: Enzymatic hydrolysis and high hydrostatic pressure (HHP) are common processing techniques in the extraction of active compounds from food materials. The aim of this study was to investigate the effects of enzymatic hydrolysis combined with HHP treatments on ginsenoside metabolites in red ginseng. RESULTS: The yield and changes in the levels of polyphenol and ginsenoside were measured in red ginseng treated with commercial enzymes such as Ultraflo L, Viscozyme, Cytolase PCL5, Rapidase and Econase E at atmospheric pressure (0.1 MPa), 50 MPa, and 100 MPa. ß-Glucosidase activity of Cytolase was the highest at 4258.2 mg-1 , whereas Viscozyme showed the lowest activity at 10.6 mg-1 . Pressure of 100 MPa did not affect the stability or the activity of the ß-glucosidase. Treatment of red ginseng with Cytolase and Econase at 100 MPa significantly increased the dry weight and polyphenol content of red ginseng, compared with treatments at 0.1 MPa and 50 MPa (P < 0.05). The amounts of ginsenoside and ginsenoside metabolites derived from red ginseng processed using Cytolase were higher than those derived from red ginseng treated with the other enzymes. Treatment with Cytolase also significantly increased the skin and intestinal permeability of red ginseng-derived polyphenols. CONCLUSION: Cytolase could be useful as an enzymatic treatment to enhance the yield of bioactive compounds from ginseng under HHP. In addition, ginsenoside metabolites obtained by Cytolase hydrolysis combined with HHP are functional substances with increased intestinal and skin permeability. © 2019 Society of Chemical Industry.

Effect of isomaltulose used for osmotic extraction of Prunus mume fruit juice substituting sucrose.

This study evaluated the applicability of isomaltulose as a sucrose substitute in the osmotic extraction of Prunus mume fruit juice. Isomaltulose (20 mM) significantly reduced the uptake of a fluorescent tracer-2-[N-(7-nitrobenz-2-oxa-1,3-diaxol-4-yl) amino]-2-deoxyglucose. Juice extracted by isomaltulose had similar pH and titratable acidity values to those of the other sugars. Citric and malic acids were the main organic acids in the extracted juices. The radical-scavenging ability of the plum juice extracted by isomaltulose was significantly higher than in juices extracted by other sugars (p < 0.05) and polyphenols content of the juice was also significantly higher than those of other sugars. The blood glucose level of P. mume juice extracted by fructose or isomaltulose was increased slowly compared to the juice extracted by sucrose. Therefore, the use of isomaltulose or an isomaltulose mixture in the manufacture of P. mume juice will help maintain health by reducing sugar intake.

Portable Agrichemical Detection System for Enhancing the Safety of Agricultural Products Using Aggregation of Gold Nanoparticles.

Organophosphorus (OP) and triazole chemicals have been commonly used as insecticides and fungicides to protect agricultural foods from harmful insects and fungi. However, these agrichemicals sometimes remain after distribution and can cause serious health and environmental issues. Therefore, it is essential to detect OPs and triazole chemicals in agricultural products. Nowadays, many detection techniques for OPs and triazole chemicals are expensive and time-consuming and require highly trained technicians. Thus, particularly rapid, simple, and sensitive detection methods are in demand for on-site screening of agrichemicals. Gold nanoparticles (AuNPs) have been utilized for applications in analytical assays and real-time monitoring in the biosensor field because of their biocompatibility and outstanding size-dependent optical properties. In this study, we used AuNPs as a detection probe, which have a size of 17 nm in diameter, a red color, and the absorbance peak at 520 nm. When imidazole was added to AuNPs mixed with the agrichemicals, the AuNPs aggregated and their colors changed to purple, causing the appearance of a new peak at 660-670 nm, which could be measured within approximately 20 s. Moreover, we developed a novel device for multiple agrichemical detections using an AuNP-aggregation-based spectrometric detection system. This portable device is light, simple, fast, and highly sensitive as well as selective. With this system, agrichemical residues can be easily detected on the spot at a low cost and in a short reaction time.

Influence of steeping solution and storage temperature on the color change of garlic.

UNLABELLED: The objective of this study was to investigate the browning of garlic under different steeping conditions and storage temperatures. The brown indices of steeped garlics showed lowest values (7.3 and 7) in 25% and 50% EtOH at 7 d of storage. The degree of browning of steeped garlics was lowest (10.2 in 25% EtOH and 10.4 in 50% EtOH) in the samples soaked for 8 h at 13 d of storage. As the storage temperature was increased from 10 to 40 degrees C, the brown indices of garlics revealed an increasing trend relative to storage time regardless of steeping treatment. Overall, the kinetic parameters showed relatively low R(2) and irregular reaction constants, but the k(o) values showed an increasing trend with temperature under a zero-order model. The highest polyphenol content within the garlic bulbs was seen in controls (without steeping treatment, 588.9 microg/g), than 0% EtOH (water, 392.5 microg/g), than 25% EtOH (211.3 microg/g), and finally 50% EtOH (155.6 microg/g). The polyphenol oxidase activity of garlic showed a similar trend to that of polyphenol content. However, the texture properties of garlics steeped with 25% and 50% did not change. PRACTICAL APPLICATION: The garlic color preferred by consumers is a creamy-white, but this is susceptible to enzymatic browning when pre-peeled and chopped. When garlic was steeped in the 25% and 50% alcohol, the browning of garlic was prevented during storage.

Selective increase in pinolenic acid (all-cis-5,9,12-18:3) in Korean pine nut oil by crystallization and its effect on LDL-receptor activity.

The aims of this study were to obtain concentrated pinolenic acid (5,9,12-18:3) from dietary Korean pine (Pinus koraiensis) nut oil by urea complexation and to investigate its cholesterol-lowering effect on the LDL-receptor activity of human hepatoma HepG2 cells. Pine nut oil was hydrolyzed to provide a low-pinolenic acid-containing FA extract (LPAFAE), followed by crystallization with different ratios of urea in ethanol (EtOH) or methanol (MeOH) as a solvent to produce a high-pinolenic acid-containing FA extract (HPAFAE). The profiles of HPAFAE obtained by urea complexation showed different FA compositions compared with LPAFAE. The long-chain saturated FA palmitic acid (16:0) and stearic acid (18:0) were decreased with urea/FA ratios (UFR) of 1:1 (UFR1), 2:1 (UFR2), and 3:1 (UFR3). Linoleic acid (9,12-18:2) was increased 1.3 times with UFR2 in EtOH, and linolenic acid (9,12,15-18:3) was increased 1.5 times with UFR3 in MeOH after crystallization. The crystallization with UFR3 in EtOH provided the highest concentration of pinolenic acid, which was elevated by 3.2-fold from 14.1 to 45.1%, whereas that of linoleic acid (9,12-18:2) was not changed, and that of oleic acid (9-18:1) was decreased 7.2-fold. Treatment of HepG2 cells with HPAFE resulted in significantly higher internalization of 3,3'-dioctadecylindocarbocyanine-LDL (47.0 +/- 0.15) as compared with treatment with LPAFAE (25.6 +/- 0.36) (P< 0.05). Thus, we demonstrate a method for the concentration of pinolenic acid and suggest that this concentrate may have LDL-lowering properties by enhancing hepatic LDL uptake.

Effects of moisture content and drying temperature on the physicochemical properties of ostrich jerky.

The objective of this study was to investigate the influence of temperature (50, 60, and 70 degrees C) and moisture content (18, 21, and 24%) on the quality ofjerky products from ostrich meat. The jerky products were evaluated by physicochemical and sensory methods. The tensile strength of the samples prepared to 24% w.b. moisture content at 50 degrees C was lowest (p < 0.05; 124 N) while those prepared under other conditions were in the range of 208-268 N (p > 0.05). The water activity of the jerky products was 0.51-0.72, and significant influence of drying temperature on protein solubility was also observed, but the samples dried at the same temperature had similar levels of soluble protein (p > 0.05) regardless of moisture content of samples. The pH of the samples dried at 50 degrees C and 60 degrees C showed little change in different moisture content, but samples dried at 70 degrees C tended to affect the pH by moisture content. Hunter a-values showed a predominantly increasing trend in all moisture levels as the heating temperature increased. The jerky product prepared to 24% w.b. moisture content at 60 degrees C showed the best sensory overall acceptability.

Thermal kinetics of color degradation of mulberry fruit extract.

The effects of temperature and pH on color degradation kinetics of the mulberry fruit extract were investigated. The absorbance at 510 nm was decreased with increase of heating time, but that at 420 nm was increased with the increase of heating time at 100 degrees C. The change of the browning index (A510/A420) was increased with increase of pH and was lower at pH 2.0 than that at pH 5.0. The browning index variation was adequately described by both the first-order and the zero-order kinetic. However, the zero-order kinetic model was proposed because of the better fit. According to the Arrhenius model, the activation energies for the browning index in the range of 80-100 degrees C for the four different pH values were 30.68 kJ/mol for pH 2.0, 35.87 kJ/mol for pH 3.0, 42.67 kJ/ mol for pH 4.0, and 43.49 kJ/mol for pH 5.0.