Integrated utilization of red radish seeds for the efficient production of seed oil and sulforaphene

Strategy for preparing of glucosinolate derivatives with outstanding functional activities based on myrosinase

Glucosinolates are a class of sulfur- and nitrogen-containing secondary metabolites that are widely present in cruciferous vegetables. Degradation products of glucosinolate, glucosinolate derivatives such as sulforaphane, sulforaphene, and iberin, have garnered interest due to their promising functional activities including anticancer, antioxidant, and antibacterial activities. As a result, these glucosinolate derivatives have substantial implications in the realms of food, medicine, and agriculture. Among the methods for preparing glucosinolate derivatives, enzymatic approach based on myrosinase stands out as a greener and more efficient alternative to chemical synthesis, underscoring the scientific and practical significance of developing myrosinase with high catalytic activity. This paper provides a systematic overview of the origin, catalytic properties, and catalytic mechanism of the key myrosinase applied for glucosinolate derivatives preparation. Meanwhile, the glucosinolate derivatives prepared via myrosinase and their functional activities are also illustrated and discussed. Furthermore, it also anticipates future research directions in myrosinase and glucosinolate derivatives.

Recent advances in the contribution of glucosinolates degradation products to cruciferous foods odor: factors that influence degradation pathways and odor attributes

As one of the most important vegetables and oils consumed globally, cruciferous foods are appreciated for their high nutritional value. However, there is no comprehensive knowledge to sufficiently unravel the "flavor mystery" of cruciferous foods. The present review provides a comprehensive literature on the recent advances regarding the contribution of glucosinolates (GSL) degradation products to cruciferous foods odor, which focuses on key GSL degradation products contributing to distinct odor of cruciferous foods (Brassica oleracea, Brassica rapa, Brassica napus, Brassica juncea, Raphanus sativus), and key factors affecting GSL degradation pathways (i.e., enzyme-induced degradation, thermal-induced degradation, chemical-induced degradation, microwave-induced degradation) during different processing and cooking. A total of 93 volatile GSL degradation products (i.e., 36 nitriles, 33 isothiocyanates, 3 thiocyanates, 5 epithionitriles, and 16 sulfides) and 29 GSL (i.e., 20 aliphatic, 5 aromatic, and 4 indolic) were found in generalized cruciferous foods. Remarkably, cruciferous foods have a distinctive pungent, spicy, pickled, sulfur, and vegetable odor. In general, isothiocyanates are mostly present in enzyme-induced degradation of GSL and are therefore often enriched in fresh-cut or low-temperature, short-time cooked cruciferous foods. In contrast, nitriles are mainly derived from thermal-induced degradation of GSL, and are thus often enriched in high-temperature, long-time cooked cruciferous foods.

Identification of glucosinolates and volatile odor compounds in microwaved radish (Raphanus sativus L.) seeds and the corresponding oils by UPLC-IMS-QTOF-MS and GC × GC-qMS analysis

The effect of microwave treatment on the content of glucosinolates (GSL) in radish seeds and volatile odor compounds in the microwaved radish seed oils (MRSO) is still unclear. In this study, a total of 13 GSL were identified and quantified in five radish seed varieties by UPLC-IMS-QTOF-MS, among which glucoraphenin, glucoraphasatin, glucoerucin accounting for up to 90 %. Total GSL decreased by 47.39-67.88% after microwave processing. Moreover, 58 odor compounds were identified in MRSO, including 6 sulfides, 12 nitriles, 2 isothiocyanates, 10 alcohols, 12 aldehydes, 5 ketones, 6 acids, and 5 others. The major odor compounds were (methyldisulfanyl)methane, dimethyltrisulfane, (methylsulfinyl)methane, 3-(methylsulfanyl)-1-propanol, methyl thiocyanate, hexanenitrile, 5-(methylsulfanyl)pentanenitrile, and 4-isothiocyanato-1-butene with odor activity value (OAV) higher than 1. The principal components analysis (PCA) results can distinguish MRSO from five different radish seed varieties, three of which (H20-18, H20-19 and H20-28) were in one group and other two (H20-23 and H20-26) were in another group. In addition, aliphatic GSL showed positive correlations with sulfides, isothiocyanates, and nitriles, while negative correlations with alcohols. This work provides a new insight into the odor contribution of GSL degradation products.

Biochemical Characterization of a Novel Myrosinase Rmyr from Rahnella inusitata for High-Level Preparation of Sulforaphene and Sulforaphane

Myrosinase is a biotechnological tool for the preparation of sulforaphane and sulforaphene with a variety of excellent biological activities. In this study, a gene encoding the novel glycoside hydrolase family 3 (GH3) myrosinase Rmyr from Rahnella inusitata was heterologously expressed in Escherichia coli BL21 (DE3). The purified Rmyr shows the highest activity at 40 °C and pH 7.0; meanwhile, its half-life at 30 °C reaches 12 days, indicating its excellent stability. Its sinigrin-, glucoraphenin-, and glucoraphanin-hydrolyzing activities were 12.73, 4.81, and 6.99 U/mg, respectively. Rmyr could efficiently degrade the radish seed-derived glucoraphenin and the broccoli seed-derived glucoraphanin into sulforaphene and sulforaphane within 10 min with the highest yields of 5.07 mg/g radish seeds and 9.56 mg/g broccoli seeds, respectively. The highest conversion efficiencies of sulforaphane from glucoraphanin and sulforaphene from glucoraphenin reached up to 92.48 and 97.84%, respectively. Therefore, Rmyr is a promising and potent biocatalyst for efficient and large-scale preparation of sulforaphane and sulforaphene.

Study on imperatorin extracted from Angelica dahurica and its UV photocatalytic reaction with collagen

Soxhlet extraction method was used to extract imperatorin from Angelica dahurica, and the extraction ratio under different extraction condition was optimized to attain the best condition. Then, XAD-16 macroporous resin was selected as the optimal resin to boost the extraction ratio of imperatorin. Afterwards, the higher purity of imperatorin (96.84±0.2%) was separated by preparative HPLC system. Next, the photocatalytic reaction between the above imperatorin and collagen which the highest levels in skin was investigated using UV-vis spectroscopy, amino acid analysis and HPLC analysis. The results showed that imperatorin reacted with collagen only under ultraviolet light which caused the denaturation of collagen, and three new products were generated. The ultraviolet products were isolated by preparative HPLC system and separately detected by high-resolution mass spectrum. The possible UV photocatalytic reaction mechanism between imperatorin and collagen is that ultraviolet light induces the increase of the activity of the imperatorin to react with the tyrosine in the collagen, resulted in the denaturation of collagen and reestablish of the normal epidermal tissue in skin.

Enzymatic preparation of oxidized viscose fibers-based biosorbent modified with ε-polylysine for dyes removal and microbial inactivation

A novel fiber-based biosorbent for dyes removal and microbial inactivation was prepared by enzymatic oxidization of viscose fibers and further modification with ε-polylysine. Glucose oxidase (GOx) was first employed as the enzyme for oxidation of viscose fibers. The consequences illustrated that the hydroxyl group on C1 position of viscose fibers was successfully oxidized with oxidation ratio of 2.43 ± 0.31%. Subsequently, ε-polylysine with average molecular weight of 4.44 ± 1.13 KDa and antimicrobial activity to E. coli of 90.48 ± 1.64 was modified with oxidized viscose fibers by lipase. Experimental results showed that oxidized viscose fibers were successfully modified with ε-polylysine with optimum degree of modification (DM) of 13.56 ± 1.05%. This oxidized viscose fiber modified with ε-polylysine (OVF-PL) displayed good dyes adsorption (or dyes removal) capacity for both anionic and cationic dyes, especially for anion dyes. Furthermore, OVF-PL showed excellent antimicrobial activity against E. coli and B. subtilis, particularly for E. coli, with GIB of 92.65%. Such fiber-based may offer a new pathway for preparing economical and efficient biosorbent for environmental remedy purpose.

Hydrolysis of radish anthocyanins to enhance the antioxidant and antiproliferative capacities

Radish anthocyanins were extracted from red radish. The total anthocyanins content (TAC) of the extracts under different extractants was optimized to reach the optimal condition. XAD-7HP was selected as the best resin to enhance TAC in the extracts. β-Glucosaccharase was chosen as the enzyme to hydrolyse radish anthocyanins. HPLC-MS analysis showed that hydrolysis resulted in an obvious change of the major constituents of radish anthocyanins. Four new constituents in hydrolysed radish anthocyanins were identified. The HPLC-MS results indicated successful hydrolysis of the attachments of glucosides and acids of radish anthocyanins. Furthermore, the FT-IR spectra of radish anthocyanins before and after hydrolysis further described the hydrolysis, which reached 53.36 ± 0.98% under the best performance. Thus, hydrolysis can significantly enhance the antioxidant and antiproliferative capacities of radish anthocyanins.

Integrated Utilization of Red Radish for the Efficient Production of High-Purity Procyanidin Dimers

Red radish was extracted by methanol to obtain crude radish procyanidin extracts. The purity of procyanidin (PP) and procyanidin dimers (PD) of crude radish procyanidin extracts under different ratios of methanol to radish was optimized to achieve the best extraction performance. Then the crude radish procyanidin extracts was, respectively, processed six macroporous resins separation to separate radish procyanidin oligomers (RPO) and polymers (RPP). Depolymerization of radish procyanidin polymers (RPP) into oligomers was then conducted. N-Acetylneuraminate lyase (NAL) was first used as the enzyme to depolymerize RPP. The depolymerization yield (DY) under different depolymerized conditions was also investigated. Results showed the DY of RPP would achieve 53.24 ± 0.35% at the best conditions. Then the high-purity procyanidin dimers was prepared by depolymerized procyanidin oligomers and PRO. Additionally, the chemical structure of the preparative radish procyanidin dimers was elucidated by high-resolution mass spectrometry and one- and two-dimensional NMR.

Extraction of α-humulene-enriched oil from clove using ultrasound-assisted supercritical carbon dioxide extraction and studies of its fictitious solubility

Clove buds are used as a spice and food flavoring. In this study, clove oil and α-humulene was extracted from cloves using supercritical carbon dioxide extraction with and without ultrasound assistance (USC-CO2 and SC-CO2, respectively) at different temperatures (32-50°C) and pressures (9.0-25.0MPa). The results of these extractions were compared with those of heat reflux extraction and steam distillation methods conducted in parallel. The extracts obtained using these four techniques were analyzed using gas chromatography and gas chromatography/mass spectrometry (GC/MS). The results demonstrated that the USC-CO2 extraction procedure may extract clove oil and α-humulene from clove buds with better yields and shorter extraction times than conventional extraction techniques while utilizing less severe operating parameters. Furthermore, the experimental fictitious solubility data obtained using the dynamic method were well correlated with density-based models, including the Chrastil model, the Bartle model and the Kumar and Johnston model.