Utilization of Mixolab<Superscript>®</Superscript> to predict the suitability of flours in terms of cake quality

The objective of this study was to determine the possibility of using Mixolab^® to predict the cake baking quality of different wheat flours. Mixolab^® data were also compared with various flour quality characteristics. The correlations between Alveoconsistograph data and the cake quality characteristics were not significant. Therefore, Alveoconsistograph test does not seem to be useful to predict the cake quality of the flour samples. Mixolab^® characteristics C2, C3, C4 and C5 were found to be significantly correlated with volume index while C5 was correlated with hardness of cakes. The parameters C2 to C5 represent the end point of the corresponding mixing stages. The flour samples which gave higher cake hardness values had higher C5 values and the samples with lower cake volumes had higher C2, C3, C4 and C5 values. It seems to be possible to estimate the texture and volume of cakes by these values. Therefore, Mixolab^® seems to be a useful tool to predict the cake making quality of flour samples.     

Effects of <Superscript>60</Superscript>Co-γ and Electron Beam Irradiation on Storage Quality of <Emphasis Type="Italic">Panax ginseng</Emphasis>

Fresh ginseng was irradiated with ⁶⁰Co-γ or an electron beam at the dose of 2 and 4 kGy and stored at 2 °C. The quality of ginseng was evaluated after 60 and 120 days. Results suggest that when the storage time was 120 days, 2 kGy EI-treated ginseng had the lowest decay rate. During the 2 storage periods, the amounts of most of 9 ginsenosides decreased with an increase in the irradiation dose. The total saponin content of both ⁶⁰Co-γ-irradiated and EI-treated samples decreased with an increase in the irradiation dose. Significant (P <?0.05) upregulation of total polysaccharide content was observed in the 4 kGy EI samples after storage. Samples irradiated at 2 or 4 kGy by electron beam irradiation had the highest concentration of total saponin and ginseng polysaccharides, respectively. Levels of most of 17 amino acids decreased with the increasing irradiation dose. Exposure to irradiation doses up to 4 kGy affected the amino acid content of fresh ginseng. Ginseng irradiated at 4 kGy by ⁶⁰Co-γ irradiation and stored for 120 days had a significantly higher activity of superoxide dismutase (P <?0.05). A significant difference was observed in the total concentration of nucleosides and nucleobases between irradiated and un-irradiated ginseng samples (P <?0.05). These data suggest that the combination of a lower irradiation dose and low temperature is an optimal condition for extending the shelf-life of fresh ginseng without detriment to its ingredients.     

Continuous cultivation of <Emphasis Type="Italic">Dunaliella salina</Emphasis> in photobioreactor for the production of β-carotene

A helix tube photobioreactor with a volume of 10 L was designed and manufactured. The facade of the reactor was designed as three-layer frame. The illumination helixes units were 16, illumination area volume was 1.5 L, illuminate specific area was 95 m⁻¹. A marine micro-alga Dunaliella salina was used as a model organism in this study. Results showed that the optimum inoculum concentration was OD₆₃₀ = 0.15 and the optimum circulation rate of culture fluid was 630 mL/h for the bioreactor. In continuous cultivation, in order to determine the optimum collection of alga solution for the highest yield of β-carotene, three different alga solution collection and addition fresh culture medium volumes were applied: 0.8, 1.5, 2.0 L/day. The biomass and extraction of β-carotene were determined in different cultivation periods. The result suggested that the optimum daily harvest of alga solution was 1.5 L/day for the cultivation of D. salina to obtain the highest production of β-carotene.     

Effects of γ-irradiation on antioxidant and antimicrobial activities and color of <Emphasis Type="Italic">Ecklonia cava</Emphasis>

Ecklonia cava (EC) was irradiated with γ-rays at doses of 3, 7, and 20 kGy. The extraction yields, total polyphenol content (TPC), DPPH radical scavenging activity, antimicrobial activity, and color of the EC extracts were assessed. The results showed that irradiation caused an increase in the extraction yields of ethanol and water. TPC was found to be significantly increased when EC powder was subjected to irradiation, followed by ethanol and water extraction. However, DPPH radical scavenging and antimicrobial activities were stable under all irradiation conditions. In the heat and pH stability tests, the DPPH radical scavenging activities of EC ethanol extracts were not influenced by irradiation. Irradiation caused an increase in the lightness and redness of EC extracts and decreased the yellowness. In conclusion, γ-irradiation increased the extraction yield and TPC and brightened the color, while maintaining the antioxidant and antimicrobial activities.     

Antioxidant and <Emphasis Type="Italic">α</Emphasis>-glucosidase inhibitory activities of different solvent extracts of skullcap (<Emphasis Type="Italic">Scutellaria baicalensis</Emphasis>)

In this study, different solvent extracts of skullcap (Scutellaria baicalensis) were assayed for their total phenol content (TPC), antioxidant activity [determined as DPPH radical scavenging activity, superoxide dismutase (SOD)-like activity, oxygen radical absorbance capacity (ORAC) assay, and comet assay], and α-glucosidaseinhibitory activity. The TPC of skullcap ranged from 9.06 mg/g gallic acid equivalents (GAE) for acetone extract (AE) to 91.8 mg/g GAE for methanol extract (ME). AE, which had a low TPC, exhibited the highest DPPH radical scavenging activity and SOD-like activity. TPC positively correlated with the ORAC assay (r=0.96, p<0.001). All skullcap extracts significantly reduced the hydrogen peroxide-induced DNA damage in human leukocytes. ME with a high TPC and ORAC value showed the highest α-glucosidase inhibition. The difference in the biological activities of the extracts may be due to the differences in their chemical structure or polarity. Therefore, the results obtained indicate that might be a potential source of compounds with health-protective effects. ME, in particular, might be a prospective therapeutic agent for diabetes.     

Development of Antimicrobial Gelatin-Based Edible Films by Incorporation of <Emphasis Type="Italic">Trans</Emphasis>-Anethole/β-Cyclodextrin Inclusion Complex

Antimicrobial activity is an attractive property for packaging materials which can extend the shelf life of products and provide microbial safety for consumers. The study aimed to analyze the physicochemical and antimicrobial properties of gelatin-based edible films containing trans-anethole as the active additive. Encapsulation with β-cyclodextrin was used as an effective way to introduce trans-anethole into gelatin matrix. The results showed that the trans-anethole/β-cyclodextrin inclusion complex could be evenly dispersed in the gelatin-based edible films with appropriate addition. The incorporation of trans-anethole conferred the edible films with good antimicrobial activity as expected, which increased with the content of trans-anethole increasing. Moreover, the addition of inclusion complex improved the tensile strength and surface hydrophobicity and reduced the moisture content of the edible films. It was interesting that the edible films presented great UV light barrier property and it was increased by the addition of inclusion complex. Overall, the antimicrobial gelatin-based edible films showed great potential as bioactive packaging materials to extend food shelf life.     

Characterization of the Polyphenolic Fingerprint of <Emphasis Type="Italic">Origanum</Emphasis> × <Emphasis Type="Italic">majoricum</Emphasis> Cambess. From Argentina by High-Performance Liquid Chromatography and Multivariate Analysis

Origanum × majoricum Cambess. is the most commonly grown oregano in Argentina. The aim of this work was to explore and describe its polyphenolic profile by high-performance liquid chromatography with diode array detection (HPLC-DAD) to support identification by classical microscopy. Remarkable homogeneity was found when defining the HPLC-DAD fingerprint with 17 characteristic common peaks. Eleven spectroscopically identified compounds were located. The method was successfully applied for the characterization of 22 samples from different productive regions of Argentina. The genetic inheritance from both progenitors of this hybrid oregano was evidenced by the presence of compounds coming from Origanum majorana L. and Origanum vulgare L. This method, combined with statistical multivariate analysis, was also useful to recognize two groups within the samples. Although O. × majoricum Cambess. must be considered the only hybrid between two species, two origins considering the subspecies level of O. vulgare L. have been morphologically differentiated for the hybrid, both with O. majorana L. These formulas were differentiated by their HPLC-DAD fingerprints. The Argentine hybrids studied appeared consistently grouped under these two profiles.     

Application of β-Cyclodextrin/2-Nonanone Inclusion Complex as Active Agent to Design of Antimicrobial Packaging Films for Control of <Emphasis Type="Italic">Botrytis cinerea</Emphasis>

The aim of this study was to develop, characterize and evaluate in vitro the efficacy of active films, based on an inclusion complex formed by β-cyclodextrin, 2-nonanone and two polymer matrices (polylactic acid and low density polyethylene). The different films were characterized by scanning electronic microscopy (SEM), differential scanning calorimetry (DSC), themogravimetric analysis (TGA), optical properties and antimicrobial activity against B. cinerea. The results showed important differences in the parameters evaluated where the level of agglomerates of additives was a key to explain these changes. Finally, microbiological analysis showed high effectiveness in reducing the Botrytis cinerea growth. The active films developed in this study were able to inhibit the growth of phytopathogenic fungus B. cinerea at different experimental conditions. The studied films have potential use for packaging fresh fruit susceptible to biological attack by this fungus.     

US consumers’ acceptability of soy sauce and <Emphasis Type="Italic">bulgogi</Emphasis>

This study investigated acceptability and consumer segmentation of soy sauce and famous Korean dish, bulgogi. A total of 123 participants evaluated intensity of 18 attributes and sensory liking of 4 commercial soy sauce samples and bulgogi samples made by aforementioned soy sauces. The overall results showed that appearance liking was the only significant different attribute among soy sauce samples and there were no significant differences among bulgogi samples. Furthermore, there was little correlation between overall liking of soy sauce and bulgogi samples. However, different segments of consumer groups were found by cluster analysis. Four and five subgroups of consumers were identified on evaluation of soy sauce samples and bulgogi samples, respectively. These results demonstrated that consumers’ different preference pattern. In conclusion, this study specified characteristics of commercial soy sauce perceived by consumers and consumers’ acceptability toward soy sauces and bulgogi made using soy sauces.     

Predicting the cookie quality of flours by using Mixolab<Superscript>®</Superscript>

The objective of this study was to determine the possibility of using Mixolab^® to predict the cookie baking quality of different wheat flours. Mixolab data was also compared with various flour quality characteristics. There were significant correlations (P < 0.001) between Mixolab stability and some of the flour quality characteristics (protein and wet gluten contents, Zeleny sedimentation value). Alveoconsistograph T value was negatively correlated with Mixolab C3, C4 and C5 values. The cookie diameter gave highly significant correlations with protein content, Zeleny sedimentation value and damaged starch content. Mixolab C3 and C4 values were highly correlated (P < 0.001) with both cookie diameter and spread ratio. A significant correlation coefficient (r = 0.556) was determined between the cookie diameter and C1–C2 value which is an indication of protein quality. The dependence of cookie diameter and spread ratio on Mixolab C3 value, damaged starch content and Zeleny sedimentation value were analyzed with multiple regression analysis and high multiple correlation coefficients were found between these parameters (r = 0.948 and 0.861, respectively).     

Integrated management of the risks of stored grain spoilage by seedborne fungi and contamination by storage mould mycotoxins – An update

Fungal spoilage of stored grains may occur when activity of water (aw) in cereal grain exceeds a critical limit enabling mould growth. Because it is not feasible to maintain all parts of large grain bulks below this critical moisture limit during prolonged storage time, an infection by seed-borne fungi is not rare in cereal grain stored under humid temperate or hot climates, inducing irreversible qualitative losses. Additionally, some fungal species produce harmful mycotoxins. The most harmful toxigenic species belong to the group of xerophilic species (genera Aspergillus and Penicillium). Because mycotoxin contamination of cereal grain is a worldwide issue for public health and a permanent concern for cereal-food industries facing the challenge of a permanent monitoring mycotoxin content in their primary matters, tolerable levels of mycotoxins are severely regulated worldwide. Mycotoxin-producing species growth is closely dependent of grain moisture levels enabling biological activity in grain ecosystem. Consequently, mould growth in stored grain bulks can be anticipated through early detection of grain and mould respiration. The prevention of mycotoxigenic fungi spoilage of stored grain can be managed by a preventive strategy. The main objective of the review was to describe the different methods, material and practices combined in such an integrated preventive approach. Some solutions potentially acceptable for the decontamination of moderately contaminated grain are also discussed.Integrated management of mould spoilage risks in stored grain is based on five pillars: i/Prevention of mould development by keeping grain moisture below the critical limit of fungal growth; ii/Accurate monitoring of grain aw and temperature changes during the storage period, associated to the monitoring of early indicators of respiration activity of storage fungi; iii/Reduction of grain bulk moistening trends by physical intervention means; iv/Use of physical treatments (ozone, grain peeling or abrasion) to limit mycotoxin contamination transfer to processed cereal products; v/Possible use of bio-competitive strains of fungi or bacteria to prevent the development of mycotoxigenic fungi in grain bulks. The future research needs on this topic are also evocated.     

Combined high pressure-mild temperature processing for optimal retention of physical and nutritional quality of strawberries (Fragaria × ananassa)

Response surface methodology was used to determine the optimal high pressure-temperature condition for the processing of strawberries for maximal inactivation of oxidative enzymes as well as best retention of nutritional and physicochemical quality following processing and during storage. High pressure treatment at 20–40 °C resulted in visual quality closest to the fresh product. High pressure combined with mild temperature caused substantial inactivation of peroxidase in strawberries with a maximum of 58% inactivation after 10 min treatment at 600 MPa and 60 °C. No significant inactivation of polyphenol oxidase was observed in strawberries under the studied condition. Combined high pressure-mild temperature processing did not have significant effect on the total polyphenol and total anthocyanin content of strawberries. However, an average of 22 ± 13% loss of total polyphenol content and 27 ± 10% loss of total anthocyanin contents was observed after 3 months of refrigerated storage.Industrial relevanceThe work described in this research is relevant to the high pressure processing of strawberries and other berry fruits. The results of the study have shown that best quality retention of strawberry products is obtained when high pressure processing is combined with vacuum packaging in high barrier packaging material and refrigerated storage since strawberry polyphenol oxidase is highly resistant to high pressure inactivation.     

Purification and partial characterization of β-glucanase produced by <Emphasis Type="Italic">Trichoderma viride</Emphasis> TP09 isolated from sewage of beer-making

As an initial investigation to improve the insoluble yeast β-1, 3-glucan solubility, a novel β-glucanase from Trichoderma viride TP09 was purified in the culture supernatant and partially characterized. By 70% saturation ammonium sulfate and chromatography on DEAE-Sepharose CL-6B column, β-glucanase was purified 28.7-fold, with recovery of 45.2% of the initial activity. The molecular weight of this enzyme was estimated to be 54.6 KD by SDS-PAGE. The optimum pH and the optimum temperature for the enzyme were 5.0 and 50 °C, respectively. The enzyme showed high stability within the range of pH 3.0–5.0 and thermostability between 30 and 70 °C. The enzyme activity was inhibited by Fe³⁺, Mg²⁺, Mn²⁺, Cu²⁺, and stimulated by Zn²⁺, Ca²⁺, Fe²⁺. Substrate specificity studies revealed the enzyme to be a β-1, 3–1, 4-glucanase. The β-glucanase showed preference for β-1, 3 linkage and β-1, 4 linkage, but had no activity on α-1, 4 and α-1, 6 linkage. The above results indicated that the enzyme extracted from T. viride TP09 of the beer-making sewage could be used as a potential predominant tool to enhance solubility of the insoluble yeast β-1, 3-glucan. These findings may lead to an enhanced solubility and expedite the progress of application in immunotherapy.     

Characterisation of volatile components of Pinotage wines using comprehensive two-dimensional gas chromatography coupled to time-of-flight mass spectrometry (GC × GC–TOFMS)

As part of the ongoing research into the chemical composition of the uniquely South African wine cultivar Pinotage, the volatile composition of nine young wines of this cultivar was investigated using comprehensive two-dimensional gas chromatography (GC × GC) in combination with time-of-flight mass spectrometry (TOFMS). Headspace solid phase micro-extraction (HS-SPME) using a carboxen/polydimethylsiloxane (CAR/PDMS) fibre was used to extract the volatile compounds from the wine matrix. Extracts were analysed using an in-house developed GC × GC system equipped with a single jet, liquid nitrogen-based cryogenic modulator. In the current study, 206 compounds previously reported in wine and related matrices have been detected in nine Pinotage wines. Positive identification for 48 compounds was performed using authentic standards, while tentative identification of 158 compounds was based on deconvoluted mass spectra and comparison of linear retention indices (LRI) with literature values. Identified compounds included esters, alcohols, aldehydes, ketones, acids, acetals, furans and lactones, sulphur compounds, nitrogen compounds, terpenes, hydrocarbons, volatile phenols and pyrans. Volatile compounds potentially capable of influencing wine aroma are highlighted. Many of the compounds were common to all 9 wines, although volatile components unique to specific samples were also observed. The results represent the most detailed characterisation of volatile constituents of this cultivar reported to date.     

Purification and characterization of <Emphasis Type="Italic">β</Emphasis>-glucosidase from <Emphasis Type="Italic">Oenococcus oeni</Emphasis> 31MBR

This study was designed to characterize a β-glucosidase from Oenococcus oeni 31MBR, a strain widely used in Chinese winemaking. An intracellular β-glucosidase (EC 3.2.1.21) was partially purified using a combination of ammonium sulfate precipitation and chromatographic methods. A single band was obtained in SDS-PAGE electrophoresis, indicating that the enzyme was highly purified and had an estimated molecular mass of 38.9 kDa. The enzyme exhibited highest activity at pH 4.5–5.0. The optimum temperature was 45 °C. Ethanol promoted the activity of this enzyme up to three times. Among the several metal ions assayed, only Mn²⁺ exhibited a partial promotion effect. The K _m and V _max values for p-nitrophenyl-β-d-glucopyranoside were 1.05 mmol/L and 0.957 nmol/min, respectively. Up to now, this study contains the first characterization of a native β-glucosidase purified from crude extracts of O. oeni 31MBR.     

Simultaneous Voltammetric Determination of Synthetic Colorants in Foods Using a Magnetic Core–Shell Fe<Subscript>3</Subscript>O<Subscript>4</Subscript>@SiO<Subscript>2</Subscript>/MWCNTs Nanocomposite Modified Carbon Paste Electrode

This paper reports the production of a novel magnetic nanocomposite based on multi-walled carbon nanotubes (MWCNTs) decorated with magnetic core–shell Fe₃O₄@SiO₂ nanoparticles which were used to fabricate a modified carbon paste electrode (Fe₃O₄@SiO₂/MWCNT-CPE). The Fe₃O₄@SiO₂/MWCNT-CPE was investigated for the simultaneous determination of sunset yellow (SY) and tartrazine (TT) in 0.1 mol/L phosphate buffer solution (pH 6.0) using square wave voltammetry (SWV). The synthesized nanocomposite was characterized by transmission electron microscopy, scanning electron microscopy, energy dispersive spectroscopy and Fourier transform infrared spectroscopy. The proposed electrode exhibits linear ranges of 0.5–100 μmol/L SY and TT with detection limits of 0.05 and 0.04 μmol/L for SY and TT, respectively. The novel proposed voltammetric method was successfully applied in the simultaneous determination of SY and TT in food products, with results similar to those obtained using a HPLC method at 95 % confidence level.

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Graphical Abstract A magnetic nanocomposite based on MWCNTs decorated with core–shell Fe₃O₄@SiO₂ was prepared and showed good ability to distinguish the response of SY and TT