Dark Soy Sauce Research Articles

Green synthesis of carbon dots from Hakka yellow wine lees: Characterization and applications for Fe3+ and NaFeEDTA sensing

In this study, Hakka yellow wine lees carbon dots (HYWL-CDs) with an average diameter of 1.75 nm are synthesized from Hakka yellow wine lees (HYWL) via a one-pot hydrothermal method. Results of X-ray photoelectron spectroscopy and FTIR reveal the presence of C=C and –OH in the HYWL-CDs. Additionally, the HYWL-CDs present excitation-wavelength dependence, with maximum excitation and emission wavelengths of 360 and 440 nm, respectively. The fluorescence of the HYWL-CDs can be quenched by Fe3+. The Fe3+ concentration is correlated linearly with the quenching rate over a linear range of 0.6–1.1 mg/mL, and the limit of detection is 0.18 μg/mL. And phenols have been shown to be present in HYWL-CDs, and the color reaction between phenols and FeCl3 is most likely the mechanism by which FeCl3 causes fluorescence burst in HYWL-CDs. Moreover, the HYWL-CDs demonstrate significant potential for detecting NaFeEDTA in iron-fortified soy sauces, the linear-fit equation was y = 185.38x + 1024.6 (R2 = 0.9995) The HYWL-CDs are loaded onto paper strips, iron-fortified straw mushroom dark soy sauce showed noticeable color changes, which allows one to differentiate normal soy sauce from iron-fortified soy sauce more conveniently and provides a new perspective for the high-value utilization of yellow wine lees.

Characterization of fragrant compounds in different types of high-salt liquid-state fermentation soy sauce from China

The aroma and sensory characteristics of 21 commercial high-salt liquid fermentation soy sauces (HLFSS) suitable for different edible methods were investigated by MS-based non-targeted metabolomics workflow using headspace solid-phase microextraction gas chromatography/mass spectrometry (HS-SPME-GC-MS) combined with sensory evaluation. A total of 325 compounds were detected, and 60 were considered aroma-active compounds. Light soy sauce (LSS) and premium soy sauce (PSS) for direct dipping contained more alcohols and esters. Aldehydes and furans were more abundant in dark soy sauce (DSS) used for stir-frying and braising. Principal component analysis (PCA) clustered LSS, DSS, and PSS into different quadrants and distinguished HLFSS of north-south origin. In addition, orthogonal partial least squares discriminant analysis (OPLS-DA) confirmed that the difference in volatile compounds of HLFSS in northern and southern China was related to local manufacturers' use of the Japanese and Cantonese fermentation processes. Sensory evaluations showed that LSS and PSS had prominent alcoholic and fruit aromas, while DSS had firmer caramel and malty aromas. Aroma-active compounds influenced regional differences in sensory attributes. The present study results will provide a theoretical basis for broadening industrial soy sauce production with different flavors.

Effects of pulsed electric field pretreatment on mass transfer kinetics of pickled lotus root (Nelumbo nucifera Gaertn.)

This study investigated the mass transfer process, penetration of seasoning, texture and sensory quality of pickled lotus root slices with pulsed electric field (PEF) pretreatment and corresponding mechanisms. Samples were subjected to 10,000 pulses in 20s (0.5, 1.0 and 1.5 kV/cm), blanched in boiling water and then soaked in brine (3% dark soy sauce and 15% NaCl). PEF pretreatment significantly enhanced water loss and NaCl gain throughout the pickling process, and higher effective diffusion coefficient (De) of PEF-pretreated samples (PEF = 17.42 and Control = 9.51, 10^-7 m2/s) resulted in a shorter period to approach the theorical osmotic equilibrium of NaCl (0.12 w/w). Furthermore, better appearance, flavor and pickled degree of samples were also attributed to PEF pretreatment. The acquired results revealed that PEF can be used to pretreat foodstuffs before pickling processing considering its effects on improving mass transfer and potential for cost reduction.

The occurrence and stability of Maillard reaction products in various traditional Chinese sauces

Traditional Chinese sauces, especially soy sauce, vinegar, and oyster sauce, provide foods with special color, flavor, and taste. However, during their manufacturing process, Maillard reaction products (MRPs) might be formed and cause adverse effects on human health. This study detected the levels of some typical MRPs in these sauces. Results showed that dark soy sauce and some vinegar products were high in 5-hydroxymethylfurfural (HMF). Moreover, dark soy sauce was significantly higher in 5-methylfurfural (MF) and methylglyoxal (MGO) than oyster sauce but lower in glyoxal (GO) than vinegar and oyster sauce, while light soy sauce had significantly higher advanced glycation end products (AGEs) than the rest three types of sauces. Besides, storage stability results indicated that MRPs increased obviously in vinegar and dark soy sauce. Finally, concentration limits/regulations of MRPs in traditional Chinese sauces should be established in the future considering their high frequency of usage and high potential of insalubrity.

Differential-based biosensor array for fluorescence-chemometric discrimination and the quantification of subtle chloropropanols by cross-reactive serum albumin scaffolding

Food contamination is a serious concern because of a high level of chemicals in food causes severe health issues. Safeguarding the public from the risk of adulterated foods has become a challenging mission. Chloropropanols are of importance to food safety and food security because they are common chemical food contaminants and believed to be carcinogenic to humans. In chemical sensing, chloropropanols are challenging analytes owing to the lacking diversity of functional groups and difficulty in targeting the hydroxyl group in aqueous environments. Moreover, because of their small molecular size, the compositions of chloropropanols remain challenging for achieving chromatographic determination. Herein, to simulate human smell and taste sensations, serum albumins, which are protein-based receptors, were introduced as low-selective receptors for differential sensing. Utilizing serum albumins, a fluorophore (PRODAN), and an additive (ascorbic acid), a differential-based optical biosensor array was developed to detect and differentiate chloropropanols. By integrating the sensor array with linear discriminant analysis (LDA), four chloropropanols were effectively differentiated based on their isomerism properties and the number of the hydroxyl groups, even at ultra-low concentration (5 nM). This concentration is far below the maximum tolerable level of 0.18 μM for chloropropanols. The sensing array was then employed for chloropropanols differentiation and quantification in the complex mixtures (e.g., synthetic soy and dark soy sauces). Leave-one-out cross-validation (LOOCV) analysis demonstrated 100% accurate classification for all tests. These results signify our differential sensing array as a practical and powerful tool to speedily identify, differentiate, and even quantify chloropropanols in food matrices.

Comparison of Biogenic Amines in Chinese Commercial Soy Sauces.

Soy sauce contains a series of biogenic amines (BAs) which is a kind of bioactive organics relating to food quality and safety. High concentration of BAs may lead to remarkable physiological and toxicological influences on human bodies, including hypotension, dizziness, and headaches. Here, we systematically compared the levels of ten main BAs among 53 Chinese commercial soy sauces using an improved high-performance liquid chromatography (HPLC) method. The results showed that the brands and production regions were both important factors accounting for the BAs’ content. The contents of Cad, Spm, Try, Phe, His, and Tyr in dark soy sauces were higher than those in light soy sauces. His and Phe in dark soy sauces were 3.7 and 1.84 times higher than in light samples, respectively. Besides, it was surprising that the content of BAs in soy sauces hugely varied from place to place. This work comprehensively compared the content of BAs in soy sauces, showing the relation between soy sauce processes and BAs, offering abundant information for further research on BAs control.

Magnetic Quantum Dot Nanobead-Based Fluorescent Immunochromatographic Assay for the Highly Sensitive Detection of Aflatoxin B1 in Dark Soy Sauce.

Herein, we synthesized bifunctional magnetic fluorescent beads (MFBs) with a distinct core/shell structure by encapsulating octadecylamine-coated CdSe/ZnS QDs (OC-QDs) and oleic acid-modified iron oxide nanoparticles (OA-IONPs) into two polymer matrixes with different hydrophobic properties. The OC-QDs and OA-IONPs were mainly distributed in the outer layer of MFBs. The resultant MFBs displayed ca. 226-fold stronger fluorescence emission relative to the corresponding OC-QDs and retained ca. 45.4% of the saturation magnetization of the OA-IONPs. The MFBs were used to purify and enrich aflatoxin B1 (AFB1) from dark soy sauce and then utilized as a fluorescent reporter of immunochromatographic assay (ICA) for the sensitive detection of AFB1. Under the optimal detection conditions, the MFB-based ICA (MFB-ICA) displayed a dynamic linear detection of AFB1 in sauce extract over the range of 5-150 pg/mL with a half maximal inhibitory concentration of 27 ± 3 pg/mL ( n = 3). The detection limits for AFB1 in sauce extract and real dark soy sauce were 3 and 51 pg/mL, respectively, which are considerably better than those of the previously reported fluorescent bead-based ICA methods. The analytical performance of the proposed MFB-ICA in terms of selectivity and accuracy was investigated by analyzing AFB1-spiked dark soy sauce samples. The reliability of the proposed method was further confirmed by ultraperformance liquid chromatography with fluorescence detection. With the combined advantages of QDs and IONPs, the resultant MFBs offer great potential as reporters of ICA for the sensitive detection of trace pollutants in complex matrix samples.

Effects of different types of soy sauce on the formation of heterocyclic amines in roasted chicken

ABSTRACTThe objective of the study was to determine the effect of different types of soy sauce and marinating time on the formation of heterocyclic amines (HCAs) in roasted chicken. Chicken breast samples were marinated with sweet, salty, light and dark soy sauce at 0, 3, 6 and 12 h (control treatment was the chicken without marinade). The concentrations of free amino acids, sugars and creatinine were determined before roasting while HCA concentrations were determined after roasting. All types of soy sauce significantly increased (p ≤ 0.05) the concentration of HCAs in roasted chicken with increasing marinating time. The highest increment of total concentration of HCAs was found in samples marinated with light soy sauce (887%) followed by dark (375%), salty (193%) and sweet (169%) at 12 h. PhIP (2-amino-1-methyl-6-phenylimidazo(4,5-b)pyridine) showed a substantial reduction in samples only momentarily marinated with sweet, salty and dark soy sauce (0 h). Free amino acids were found to be more strongly correlated with the formation of HCAs than reducing sugars or creatinine.

Chemical Profiling of Different Types of Soy Sauce and the Relationship with its Sensory Attributes

AbstractFour types of soy sauce which are widely consumed and commercially available in Southeast Asia, namely sweet, salty, light and dark soy sauce were discriminated. A comprehensive chemical profiling such as sodium chloride, sugars, organic acids, total nitrogen and free amino acids were determined. The sensory attributes were determined using the Quantitative Descriptive Analysis (QDA) and their relationship with chemical profiles were analyzed by multivariate approach using orthogonal partial least square discriminant analysis (OPLS‐DA). Results showed that sugar was the dominant compound in sweet, salty and dark soy sauce. The sensory attributes such as color, caramel odor, viscosity and sweetness taste increased the overall acceptance in these types of soy sauce. In light soy sauce, sodium chloride, total nitrogen and free amino acids appeared to be dominant compound. It was found that saltiness and umami taste were the important sensory attributes that well‐characterized the taste of light soy sauce.Practical ApplicationsIn Southeast Asia, sweet, salty, light and dark types of soy sauce are very popular and commonly used in cooking and as a table condiment. Variations in raw materials used and different production process of different types of soy sauce may contribute to the different chemical profiles and sensory attribute of soy sauce. This aims of this study were to provide general understanding of the chemical characteristics in sweet, salty, light and dark types of soy sauce and highlight the differences between them. In addition, the results of this study can be used to provide additional data for the purpose of standardization and quality improvement of soy sauce production.

Rapid detection of total nitrogen content in soy sauce using NIR spectroscopy

Xu J., Huang F., Li Y., Chen Z., Wang Y. (2015): Rapid detection of total nitrogen content in soy sauce using NIR spectroscopy. Czech J. Food Sci., 33: 518–522. A method for the rapid and nondestructive determination of total nitrogen content in soy sauce was explored. Pre diction models were established using near-infrared spectroscopy combined with each of the following techniques: partial least squares (PLS), interval PLS, synergy interval PLS (siPLS), and backward interval PLS. Results showed that each improved forecast model was better than the PLS model. The siPLS method exhibited the best performance. The full spectrum of light soy sauce was divided into 20 subintervals. The combination of four subintervals, namely, 6, 11, 13, and 18, showed the best effect, with a correlation coefficient of 0.9977 and an RMSECV of 0.0198. The full spectrum of dark soy sauce was divided into 20 subintervals. The combination of three subintervals, namely, 14, 17, and 19, showed the best effect, with a correlation coefficient of 0.9818 and an RMSECV of 0.0640. Therefore, the siPLS method can realise a rapid and accurate detection of total nitrogen content in soy sauce.

Morphological evaluation of the protective role of dark soy sauce against acrylamide induced neurotoxicity in albino rats.

Acrylamide (ACR) exposure is associated with neurotoxicity, carcinogenicity, and reproductive toxicity. The use of soy sauce as a condiment is common and it has been found that it possesses high antioxidant activity. The objective of the current study is to evaluate the protective role of dark soy sauce (DSS) against ACR-induced neurotoxicity in rats. Thirty-five adult male rats were divided into four groups: control, ACR given for 4 weeks, DSS given for 4 weeks before ACR, and DSS given with ACR for 4 weeks. The trigeminal ganglia and cerebellum were dissected and processed for histological staining with haematoxylin and eosin and immunohistochemistry for synaptophysin (SYP) and morphometric analysis. In the trigeminal ganglia, ACR group showed central chromatolysis, degeneration and cell loss. DSS before ACR group had less marked changes in the neuronal architecture, while in ACR with DSS group, better preservation was observed. In the cerebellum, ACR group showed shrunken Purkinje cells and nuclear pyknosis. Spacing and dissociation between Purkinje layer and other layers was seen. DSS before ACR group showed few degenerated Purkinje cells with normal pattern of the other layers of cerebellar cortex. ACR with DSS group showed less disturbed cerebellar layers architecture. Cerebellar SYP immunoexpression and its area per cent were decreased in ACR group compared with the control. It increased in both DSS treated groups, specifically DSS concomitantly given with ACR. ACR exerted marked cellular degenerative effects and administration of DSS and ACR at the same time had neuroprotective effect. DSS treatment before ACR exposure gave only marginal improvement.

Rapid measurement of antioxidant activity in dark soy sauce by NIR spectroscopy combined with spectral intervals selection and nonlinear regression tools

This paper attempted to show the feasibility of measuring the antioxidant activity in dark soy sauce by NIR spectroscopy technique. Chemometrics on spectral intervals selection and nonlinear regression tools were systematically studied in the calibrating model. First, the optimal spectral intervals were selected by synergy interval-partial least square (Si-PLS). Then, kernel PLS (KPLS) and back propagation artificial neural network (BPANN), as two nonlinear regression tools, were performed comparatively to calibrate models based on optimal spectral intervals, called Si-KPLS and Si-BPANN models, respectively. These models were optimized by cross-validation, and the performance of the final model was evaluated according to correlation coefficient (Rp2) and root mean square error of prediction (RMSEP) in the prediction set. The results showed that the Si-BPANN model was superior to other models, and the optimal result was achieved with Rp2 = 0.9769 and RMSEP = 0.0221 in the prediction set. This work demonstrated that total antioxidant capacity in dark soy sauce could be measured by NIR spectroscopy technique, and Si-BPANN showed its superiority in model calibration.

Antiglycation and Antioxidant Properties of Soy Sauces

Diabetes-induced hyperglycemia increases formation of advanced glycation end products (AGEs) and metal-catalyzed production of free radicals. This study compared the antioxidant capacities of dark and light soy sauces of different brands and investigated their abilities to inhibit AGEs and whether their mechanism of action was pre- or post-Amadori or involved chelation of transition metals. The antioxidant capacities of soy sauces were compared using the 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonate) method and by measuring their total phenolic contents. Model proteins (lysozyme, albumin) were glycated using fructose with or without soy sauces with subsequent analysis of cross-linked AGEs by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The effect of soy sauces on pre- and post-Amadori inhibition of AGEs was investigated by measuring fructosamine and AGEs following reincubation of ribose-glycated (ribated) lysozyme, respectively. Dark soy sauces had higher antioxidant capacities and phenolic content and were more effective inhibitors of post-Amadori-derived cross-linked AGEs. However, light soy sauces were more effective at inhibiting fructosamine and had more potent metal chelation properties. This study reports the antiglycation properties of soy sauces, but further studies are required to determine the constituents responsible for this effect and whether soy sauce consumption can reduce oxidative stress and AGEs in diabetic subjects.

Relationships between antioxidant activity and quality indices of soy sauce: an application of multivariate analysis

SummaryAntioxidant activities (AA) and quality indices including the contents of total nitrogen, amino nitrogen, total acidity, sodium chloride, total solids (TS), non‐salt soluble solids and Browning Index (BI) were determined in forty‐one commercial soy sauces. The relationships between quality indices and AA were elucidated by multivariate analysis techniques. Results showed that production location, fermentation process and styles had significant (P < 0.05) impacts on the characteristics of soy sauces. Satisfactory discrimination between dark and light soy sauces was achieved by principal component analysis. Using cluster analysis, the group of dark soy sauce with strong AA was obtained. Results from partial least squares regression (PLS) showed that TS and BI were two major indices contributing to the AA of soy sauce. Moreover, a PLS model was constructed to effectively predict AA of soy sauces based upon quality indices.

The moderating role of dark soy sauce to acrylamide-induced oxidative stress and neurophysiological perturbations in rats

To evaluate the protective effects of dark soy sauce (DSS) against acrylamide (ACR)-induced neurotoxicity in rats, 60 adult Sprague Dawley female rats were given DSS (0.5 ml/kg body weight/day) before, after, and during ACR treatment (10 mg/kg body weight/day) for 8 weeks in total. Treatment only with ACR resulted in a significant increase in lipid peroxidation level, lactate dehydrogenase, and serum creatine kinase activity, but a significant decrease in superoxide dismutase activity in brain homogenate. Moreover, serum serotonin, corticosterone, 3, 5, 3′-triiodothyronine, and L-thyroxine, thyroid stimulating hormone, estradiol, progesterone, and plasma adrenaline decreased significantly in ACR rats. Treatment with DSS before, during, and after ACR treatment partially antagonized the effects induced by ACR. In conclusion, DSS exhibited a protective action against ACR-induced oxidative stress and biochemical perturbations in rats; and treatment with DSS during ACR exposure was more effective than after or before ACR treatment.

Protective role of dark soy sauce against acrylamide-induced neurotoxicity in rats by antioxidative activity

Dark soy sauce (DSS) exerts antioxidant activity in vitro or in vivo. To test the possibility of chemoprevention by such dietary supplements on acrylamide (ACR)-induced subacute toxicity, Sprague-Dawley male rats were administered DSS dissolved in water (0.5 ml/kgbw•d) for 2 weeks after, before or during ACR exposure (0.2 mg/L in distillate water). DSS significantly improved the body weight gain, relative brain weights, and the gait abnormalities of ACR-treated rats when DSS treated at the same time as ACR-exposure (p < 0.05). DSS significantly improved the axonal degeneration, the ratio of myelinated nerves < 3 μm in diameter, degree of central chromatolysis of the ganglion neurons in peripheral nerves, and numbers of SYP (+) aberrant dots per mm cortex in the cerebellar molecular layer of ACR-treated rats no matter before, after, or during ACR-exposure (p < 0.05). DSS significantly decreased the malondialdehyde level and increased the superoxide dismutase activity in brain of ACR-treated rats when DSS treated during ACR-exposure (p < 0.05). These findings suggest that DSS plays a protective role against ACR-developed neurotoxicity and, partly at least, through an anti-oxidative mechanism. And it is worthy to note that DSS treatment at the same time as ACR exposure plays a more effective protective role than before or after ACR exposure.

The identification of antioxidants in dark soy sauce

Soy sauce is a traditional fermented seasoning in Asian countries, that has high antioxidant activity in vitro and some antioxidant activity in vivo. We attempted to identify the major antioxidants present, using the 2,2′-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) assay as a guide. 3-Hydroxy-2-methyl-4H-pyran-4-one (maltol) was one of several active compounds found in an ethyl acetate extract of dark soy sauce (DSS) and was present at millimolar concentrations in DSS. However, most of the antioxidant activity was present in colored fractions, two of which (CP1 and CP2) were obtained by gel filtration chromatography. Their structural characteristics based on nuclear magnetic resonance (NMR) and electrospray-ionization time-of-flight mass spectrometry (ESI-TOF-MS) analysis suggest that carbohydrate-containing pigments such as melanoidins are the major contributors to the high antioxidant capacity of DSS.

Cautions in the use of biomarkers of oxidative damage; the vascular and antioxidant effects of dark soy sauce in humans

Dark soy sauce (DSS) is a powerful antioxidant in vitro. We investigated whether this effect could occur in vivo and improve vascular function. Healthy human subjects were given DSS or placebo meals in a randomized, crossover study. Blood and urine were sampled before and 1, 2, 3, and 4 h after the meal for F 2-isoprostanes (total, free, and esterified) and 8OHdG measurements. Blood pressure, vascular augmentation index (AIx), and heart rate (HR) were also measured. Plasma total F 2-isoprostanes significantly decreased 3 h after placebo and the decrease was greater for DSS. Plasma free and esterified F 2-isoprostanes were also significantly decreased after DSS. Both placebo and DSS meals increased urinary F 2-isoprostanes at 1 h but not thereafter, and lowered urinary 8OHdG levels, DBP and AIx, and increased HR. We conclude that DSS decreases lipid peroxidation in vivo. However, oxidative damage biomarkers changed after the placebo meal, a phenomenon to consider when designing interventional studies.

Odor Recognition of Soy Sauce by Semiconducting Polymer Sensors

In order to recognize the odor of soy sauce, an electronic nose having 32 different semiconducting polymers was used. Prior to the odor analysis of soy sauce, the effect of water vapor in a sample gas on the change in resistance of a sensor was examined using two kinds of spray-dried coffee that exhibited different odors. The effect of the water vapor was eliminated by controlling the humidity of the reference air during baseline determination. Two dark soy sauces produced by different companies were used. The electronic nose recognized the difference in the odors of the soy sauces, of which point mappings formed clusters of odor apart from each other. The change in odor with time caused by exposure to air was also detected.

Determination of 1,3-Dichloropropanol in Soy Sauce and Related Products by Headspace Gas Chromatography with Mass Spectrometric Detection: Interlaboratory Study

An interlaboratory study was performed to evaluate the effectiveness of a headspace gas chromatography (GC) method for the determination of 1,3-dichloro-propan-2-ol (1,3-DCP) in soy sauce and related products at levels above 5 ng/g. The test portion is mixed with an internal standard (d5-1,3-DCP) and ammonium sulfate in a sealed headspace vial. After achieving equilibrium, the headspace is sampled either by gas-tight syringe or solid-phase microextraction (SPME) and analyzed by GC with mass spectrometric detection. 1,3-DCP is detected in the selected-ion mode (monitoring m/z 79 and 81 for 1,3-DCP and m/z 82 for the deuterated internal standard) and quantified by measurement against standards. Test materials comprising soy, dark soy, mushroom soy, and teriyaki sauces, both spiked and naturally contaminated, were sent to 9 laboratories in Europe, Japan, and the United States; of these, 5 used SPME and 4 used syringe headspace analysis. Test portions were spiked at 5.0, 10.0, 20.0, 100.0, and 500.0 ng/g. The average recovery for spiked blank samples was 108% (ranging from 96-130%). Based on results for spiked samples (blind pairs at 5, 10, 20, 100, and 500 ng/g) as well as a naturally contaminated sample (split-level pair at 27 and 29 ng/g), the relative standard deviation for repeatability (RSDr) ranged from 2.9-23.2%. The relative standard deviation for reproducibility (RSDR) ranged from 20.9-35.3%, and HorRat values of between 1.0 and 1.6 were obtained.