Lebensmittel-Wissenschaft und-Technologie

Published by Elsevier
Print ISSN: 0023-6438
The antioxidant and antimicrobial effects of equivalent concentrations of fresh garlic (FG), garlic powder (GP) and garlic oil (GO) were investigated against lipid oxidation and microbial growth in raw chicken sausage during storage at 3 degrees C. The antioxidant activities were compared to that of a standard synthetic antioxidant; butylated hydroxyanisole (BHA). The initial mean levels of thiobarbituric acid (TBA) value and peroxide value (POV) were 0.140 and 6.32, respectively. However after 21 days of storage, TBA and POV ranged from 0.151 to 4.92, respectively, in FG (50 g/kg) formulated samples to 0.214 and 8.64, respectively, in GO (0.06 g/ kg) formulation. Addition of either garlic or BHA (0.1 g/kg) significantly delayed lipid oxidation when compared with control. The antioxidant activities of the various materials added followed the order FG>GP>BHA>GO. On the other hand, the initial aerobic plate count (APC) in the samples was 4.41 log(10) CFU/g. Addition of FG (30 g/kg) or GP (9 g/kg) significantly reduced the APC and, subsequently, the shelf-life of the product was extended to 21 days. However, addition of GO or BHA resulted in no significant difference in APC when compared with control. Sensory analysis indicated that FG had a significant stronger flavor than the other sausage formulations. The results suggest that fresh garlic and garlic powder, through their combined antioxidant and antimicrobial effects, are potentially useful in preserving meat products.
The effects of sodium lactate (NaL) and sodium chloride (NaCl), either alone (30 g/kg) or in combination (20+20 g/kg), on the microbiological and chemical quality of raw ground beef during vacuum-packaged storage at 2 degrees C were investigated. The results showed that addition of NaL alone or in combination with NaCl significantly delayed the proliferation of aerobic plate counts, psychrotrophic counts, lactic acid bacteria and Enterobacteriaceae and extended the shelf life of the product up to 15 and 21 days, respectively, versus 8 days only for control. Over the storage time (21 days), NaL maintained the ground beef at almost constant pH, while the pH of control or NaCl-treated samples significantly decreased. Lipid oxidation (TBA value) was not affected by addition of NaL. At storage day 21 however, TBA values of both NaL-treated (0.309) and control (0.318) samples were significantly lower than those of samples treated with NaCl (0.463). The combination of NaCl with NaL significantly reduced the oxidative changes caused by NaCl (0.384 versus 0.463). Therefore, NaL alone or in combination with NaCl could be utilized successfully to reduce the microbial growth, maintain the chemical quality, and extend the shelf life of ground beef during refrigerated storage.
In this study, the gel strength and visible microstructure of fat containing β-lactoglobulin–κ-carrageenan gels were investigated using puncture testing and confocal scanning laser microscopy, respectively. The gel strength was closely linked to the visible microstructure of the whey protein network as stained with Rhodamine B. Covalent labelling of κ-carrageenan with FITC prior to gel formation enabled localisation of the hydrocolloid phase, but caused a significant drop in the gel strength. This effect coincided with the observed reduction of the κ-carrageenan intrinsic viscosity, which was found to be a result of the labelling process. The use of a novel dye, V03-01136, for the staining of fat allowed for the specific and concurrent visualisation of the protein, hydrocolloid and fat phases under the conditions applied in the study.
The binding of phenolic compounds to ribulose-1,5-diphosphate carboxylase (RubisCO) is known to give rise to some digestive problems in human beings. In fact, the biological value of protein and hence the Protein Efficiency Ratio and Net Protein Utilization decrease drastically. For this reason the binding of phenolic compounds (e.g. rutin and chlorogenic acid) to ribulose-1,5-diphosphate carboxylase (RubisCO) was studied by means of ultrafiltration techniques in order to better elucidate the nature of this interaction and the factors influencing it in an attempt to limit or avoid it. RubisCO behaviour was also compared with that of Bovine Serum Albumin. A multivariate approach was used to determine the most influencing variables and their effects on binding. A classical binding study with the aim of determining the binding stoichiometry was also carried out. pH was found to be the most important variable affecting the binding of rutin to RubisCO as well as rutin to Bovine Serum Albumin while contact time became relevant when operating in sub-alkaline pH conditions. Classical binding analysis was carried out at pH 7.0 to 7.3 by both direct partition and diafiltration methods. A total number of five binding sites was determined, with two kinds of binding mechanisms, one of which was hydrophobic. The diafiltration method can be considered a useful tool when high affinity interactions are studied; RubisCO protein stability was disturbed by stirring, but this allowed an increased affinity of aggregated RubisCO to chlorogenic acid to be noted. This might have important consequences on RubisCO extraction technology since the most critical phase of phenolic contamination is the crystallization-precipitation step.
Optimization of protein extraction for food use by wet fractionation procedure requires knowledge of the possible degradation processes which usually accompany the purification procedures and of the basic molecular features of the particular protein. Proteolytic degradation of ribulose-1,5-bisphosphate carboxylase (RuBPcase) observed in crude extracts ofSpirulina platensiswas partially inhibited by the addition of phenyl-methyl-sulphonyl-fluoride as a proteinase inhibitor. The RuBPcase purified to electrophoretic homogeneity by a laboratory method was characterized for molecular weight, isoelectric point, solubility as a function of pH and ionic strength, and heat stability. Since degradation of purified plant RuBPcase is related to the redox state of enzyme thiol groups we have investigated the relationship between the number of oxidized thiol groups and the residual activity in the purified preparation of RuBPcase fromSpirulina platensis. Furthermore, the susceptibility of the enzyme to various transition metals, able to catalyse the oxidation of thiol groups, was evaluated and the functional role of thiol groups for the maintenance of the native structure of RuBPcase is discussed. The results obtained are presented and discussed in view of the potential industrial extraction of RuBPcase fromSpirulina platensis.
We assessed the effect of electron beam irradiation of packaged fresh blueberries at doses greater than 1.0 kGy on the quality attributes of the fruits. Irradiation experiments were conducted using a 10 MeV (18 kW) linear accelerator with single beam fixture. Fruits were stored at 5 °C and 70.4% RH for 14 days and tested at days 0, 3, 7 and 14 for physico-chemical, textural, microstructural, and sensory characteristics. Control samples consisted of non-irradiated fruits. Irradiation at doses higher than 1.1 kGy did affect (P<0.05) the texture of blueberries as the fruits became considerably softer and less acceptable throughout storage. Only irradiation at 3.2 kGy affected the color of blueberries by the end of storage. Irradiation slightly reduced the respiration rates of the blueberries by the end of storage. In terms of overall quality, texture and aroma, only fruits exposed to 3.2 kGy were found unacceptable by the sensory panelists. Irradiation at the dose levels used in this study did not affect the density, pH, water activity, moisture content, acidity and juiciness of blueberries. Electron beam irradiation of blueberries up to 1.6 kGy is a feasible decontamination treatment that maintains the overall fruit quality attributes.
Whole, farmed Coho salmon (Oncorhynchus kisutch) were sacrificed in slurry ice (−1.5 °C) then stored in this medium for further processing after 0, 5 and 9 days. They were cooked whole and the flesh was evaluated by sensory, physical and chemical techniques to establish if significant changes had occurred as a result of the storage period. Initial samples from harvest were also evaluated for comparison. There was evidence of increases in trimethylamine, lipid hydrolysis, lipid oxidation (anisidine and thiobarbituric acid values) and interaction compound formation (fluorescence and browning measurements). The fish structure became more breakable with longer storage but there were no changes in sensory assessments for rancid and putrid odours, so that scores were less than 0.5 on a 11-point scale. From the present results, primary and secondary lipid oxidation development and further interaction compound formation appear to be the main measurable indicators of quality changes in cooked Coho salmon. However, and according to sensory appreciation, slurry ice has shown to be a suitable medium for previous storage of Coho salmon for periods of up to 9 days.
The feasibility of measuring caffeine content in instant green tea and granules was investigated by Fourier Transform Near-Infrared (FT-NIR) spectroscopic technique. A calibration model was developed using pure caffeine standards of varying concentrations in the near-infrared region (4000–12000 cm−1). The developed model was validated using test validation technique. FT-NIR spectroscopy with chemometrics, using the PLS–first derivative plus straight line subtraction method could predict the caffeine content in tea samples accurately up to an R2 value greater than 0.98 and a standard error of prediction (SEP) value less than 2.0 with 6 factors in the prediction model. The developed model was applied to predict caffeine content in tea samples within 2–5 min. The developed procedure was further validated by recovery studies by comparing with UV spectroscopic method of caffeine determination.
High-quality regression models of gas chromatographic retention indices were generated for OV-101 (R=0.997), DB-1 (R=0.998), DB-5 (R=0.997), and DB-Wax (R=0.982) using 91, 57, 94, and 102 compounds, respectively. The models were generated using a second-order equation including the cross product utilizing two easily obtained variables, boiling point and the log octanol-water coefficient. Additionally, a method for determining outlier data (the GOodner Outlier Determination (GOOD) method) is presented, which is a combination of several outlier tests and is less prone to discarding legitimate data.
Although chemical reactivity in solid food systems has been studied as a function of water activity and glass transition, the possible effects of water mobility on chemical reactions have not been investigated. The effect of the glass transition on water mobility at constant temperature and water content was determined. The relationship between the experimentally determined water mobility in polyvinylpyrrolidone (PVP) systems and chemical reactivity data from the same PVP systems was evaluated. Water mobility, as determined via 17O-NMR, was not affected by the glass transition; PVP systems at constant water activities and water contents, but different physical states (glassy and rubbery), had the same water mobility. An evaluation of four chemical reactions showed no relation between water mobility and kinetic data. The effect of water on chemical reactions is multidimensional and cannot be reduced to a single physicochemical parameter.
The aim of this study was to investigate the in vitro antileukemic activity of hot water (HW) or juice extracts of 17 frequently used fruits and vegetables in Taiwan. The cytotoxic effect against K562, P3HR1, Raji, and U937 leukemia cells was evaluated by the colorimetric XTT assay. Results showed that only HW extract of the fruit rind of Garcinia mangostana exhibited potent antileukemic activity. G. mangostana showed a significant cytotoxic effect against K562 and Raji cells (P<0.05) with IC50's of 61.0±9.9 and 159.2±12.1 μg/mL, respectively. It also possessed moderate anti-U937 activity, but was less effective against P3HR1 cells. The selectivity indices of G. mangostana on K562, U937, and Raji cells were higher than that of Catharanthus roseus, a reference compound. The other 16 tested samples were moderate, mild or less in their antileukemic activity. In conclusion, the promising and encouraging antileukemic activity of G. mangostana merit further investigation on its active component(s) and underlying mechanism(s) of action.
HCA dendrogram obtained from 1 H NMR spectra from different vinegar types 
HCA dendrogram obtained from 1 H NMR spectra from different vinegar types (dotted line: similarity index of 0.06 and dashed line: similarity index of 0.37).
PCA score plot (PC1 Â PC2) showing the discrimination between all vinegar types studied. 
This work describes using 1H NMR data and pattern recognition analysis to classify vinegars. Vinegar authenticity is linked to raw ingredient source and manufacturing conditions. Application of PCA and HCA methods resulted in the natural clustering of the samples according to the raw material used. Wine vinegars were characterized by a high concentration of ethyl acetate, glycerol, methanol and tartaric acid, while glycerol and ethyl acetate signals were not visible in alcohol/agrin vinegars. Apple vinegars showed to be richer in alanine. The KNN, SIMCA and PLS-DA methods were used to build predictive models for classification of vinegar type wine, apple and alcohol/agrin (27 samples – 22 as training set). The models were tested using an independent set (5 samples), no samples were wrongly classified. Validated models were used to predict the class of 21 commercial samples, which, as expected, were correctly classified. Eight commercial vinegars (honey, orange, pineapple and rice) were discriminated from these samples using PCA method. Honey vinegars did not present ethanol signals and pineapple vinegars presented the largest amount of tartaric acid. Rice and orange vinegars are richer in lactic acid and did not present the methanol signal. Alanine signals were not visible in orange vinegars.
The water-soluble volatile components of fresh tomatoes were isolated by liquid-liquid continuous ether extraction of filtered blended tomato and separated from non-volatiles by high flow dynamic headspace sampling, after careful evaporation of the ether. Capillary GCMS analysis identified the important aroma compound 2,5-dimethyl-4-hydroxy-3(2H)-furanone (furaneol) and the related compound 5-methyl-4-hydroxy-3(2H)-furanone occurring in the fresh tomato at concentrations of the order of 2 mg and 10 mg/kg of tomato respectively. From the odor threshold and concentration evidence it seems probable that Furaneol contributes to fresh and processed tomato aroma.
In this study, the antioxidant activity of water and ethanol extracts of fennel (Foeniculum vulgare) seed (FS) was evaluated by various antioxidant assay, including total antioxidant, free radical scavenging, superoxide anion radical scavenging, hydrogen peroxide scavenging, metal chelating activities and reducing power. Those various antioxidant activities were compared to standard antioxidants such as butylated hydroxyanisole (BHA), butylated hydroxytoluene (BHT), and α-tocopherol. The water and ethanol extracts of FS seeds showed strong antioxidant activity. 100 μg of water and ethanol extracts exhibited 99.1% and 77.5% inhibition of peroxidation in linoleic acid system, respectively, and greater than the same dose of α-tocopherol (36.1%). The both extracts of FS have effective reducing power, free radical scavenging, superoxide anion radical scavenging, hydrogen peroxide scavenging, and metal chelating activities. This antioxidant property depends on concentration and increasing with increased amount of sample. In addition, total phenolic compounds in the water and ethanol extracts of fennel seeds were determined as gallic acid equivalents. The results obtained in the present study indicated that the fennel (F. vulgare) seed is a potential source of natural antioxidant. Although, the tests presented here show the usefulness of FS extracts as in vitro antioxidants it still needs to be that this extracts show their activity in emulsions, biological systems, health implications or dry foods.
Dielectric properties (DP) are the main parameters that provide information about how materials interact with electromagnetic energy during dielectric heating. These properties have gained great importance and applications for foods that are subjected to novel microwave (MW) or radio frequency (RF) heating treatments. The knowledge of the DP of a determined foodstuff is fundamental in order to understand and model the response of the material to the electromagnetic field, at certain desired frequencies and temperatures. Through the last years, many potential applications of electromagnetic heating for foods have emerged and been published in the literature; however, new uses or research in food products to be treated with MW or RF may be limited due to lack of DP data. This review provides an overall introduction and definition of the DP, factors that affect them, methods for their determination, as it also includes reported DP data for foods after the year 2000. DP values were grouped depending on the nature of foods, such as: 1) fruits and vegetables, 2) flour, dough and bread, 3) nuts, 4) coffee grains, 5) meats, fish and seafood, 6) dairy products, 7) eggs and egg products and 8) liquid fluids. We consider that this paper is a useful reference that contains current and valuable information on the DP of foods, which can be available and used for further developments employing MW or RF heating food technologies.
The Plackett–Burman experimental design was used to evaluate the medium components for lipase production by Rhizopus arrhizus in submerged batch fermentation. Twelve medium components with three dummy variables were studied in this experimental design. The most significant variables affecting lipase production were found to be olive oil, peptone, KH2PO4, CaCl2·2H2O and MgSO4·7H2O. Maximum lipase activity (3.98 U mL−1) and maximum cell mass concentration (5.62 g L−1) were obtained using the optimised medium. Unstructured kinetic models were analysed to simulate the experimental values of cell growth, lipase activity and glucose concentration. The logistic model for cell growth, the Luedeking–Piret model for lipase production and a modified Luedeking–Piret model for substrate utilisation were found to accurately predict the fermentation kinetics. The estimated values of the kinetic model parameters, α and β, for lipase production indicate that the lipase production by R. arrhizus is growth-associated.
Sensory scores of the fresh VOO samples (at T 0 ). 
Correlation of malaxation temperatures with oxidative stability of the VOO. 
HPLC–DAD–MS/MS phenolic profiles of the Cor oils ( T 3 ) obtained at the three different malaxation temperatures. 1, 3,4-DHPEA-EDA; 2, p -HPEA-EDA. 
Phenolic profile ( l 1⁄4 280 nm) of the F/L and Cor oils at 35 C ( T 9 ): 1, 3,4-DHPEA; 2, p -HPEA; 3, vanillic acid; 4, vanillin; 5, 3,4-DHPEA-Ac; 6, 3,4-DHPEA-EDA; 7, 3,4- 
Trends of the phenolic classes of the VOO samples during the 12 months of storage. 
Within the European Union, indications of ‘first cold pressing’ and ‘cold extraction’ can only be used for virgin olive oil (VOO) obtained below 27 °C from mechanical processing. Three different malaxing temperatures (25, 35 and 45 °C) are here evaluated for the quality of the VOO obtained in a continuous industrial plant. The oils were stored at room temperature in the dark for 12 months. Initially, oil obtained from a blend of Frantoio/Leccino cultivars (F/L) had higher acidity and peroxide levels and lower phenolic content than a Coratina cultivar (Cor). The oxidative stability of the oils positively correlated with malaxation temperature (F/L, R2 = 0.818; Cor, R2 = 0.987) as the phenolic content was directly proportional to the temperature (F/L, R2 = 0.887; Cor, R2 = 0.992). Only oils obtained at 45 °C were rejected because of ‘heated or burnt’ off-flavour. Decarboxymethylation of secoiridoids and further hydrolysis of phenolic esters occurred during storage. The oxidation products of derivatives of tyrosol and hydroxytyrosol were detected after nine months in both the F/L and Cor samples. Thus, VOO obtained at a processing temperature lower than 27 °C does not show higher chemical and sensory qualities than VOO obtained at 35 °C.
Nutritional and antioxidant properties of phenolic compounds are important in relation to human health and palatability of products. 3,4-Dihydroxyphenylglycol (DHPG) is a strong antioxidant found in small amounts in virgin olive oil and table olives, with an antioxidant activity even higher than that of the powerful hydroxytyrosol. The origin of this antioxidant is completely unclear since has never been reported as a free plant metabolite. In this respect possible precursors of DHPG have also been discussed in this study. The presence of soluble compounds that either contain DHPG in their molecular structure or act as substrates for its synthesis has been showed for the first time. The quantities of DHPG recovered in olive drupe tissue by thermal treatment exceed widely the values indicated in the literature, showing the release or formation of additional DHPG from precursors after heating. In addition, DHPG obtained under certain extraction conditions from fresh solid waste of two-phase olive oil extraction systems (alperujo) is its most important phenolic compound. Therefore, the solid olive waste is a good source of this simple monomer phenol. The chemical structure, purity and racemic nature of isolated DHPG were also analysed for the first time by NMR experiments.
Odor threshold studies of highly purified forms of 2-ethyl-3,5-dimethypyrazine and 2-ethyl-3,6-dimethylpyrazine in water solution showed that the -3,5- isomer was a much more potent odorant with a threshold of 0.04 μg / L compared to that of 8.6 μg /L for the -3,6- isomer, thus confirming reported aroma extract dilution analysis air diluted GC effluent threshold measurements on these compounds.
Epidemiological studies have shown an inverse relationship between consumption of nutritive/non-nutritive foods of plant origin and colon cancer incidence. This study was conducted to determine the effect of green tea, phytic acid, and inositol at 2 g/100 ml levels singly and in combination on azoxymethane (AOM) induced colon tumors in Fisher 344 male rats. After an acclimatization period of one week, 8 groups of rats (15 rats each) were initially assigned to consume AIN 93G and later AIN 93M diet. All treatments were given in drinking water. All the rats received 16 mg/kg body mass AOM, two s/c injections at seven and eight week of age. Rats were killed at 46 week of age by CO2 euthanasia. Tumor incidence (percent) and tumors per tumor-bearing rat (TBR) in the control were significantly higher (P<0.05) than all treatment groups. Glutathione-S-transferase (GST) activity was significantly higher in treatment groups compared to control. These findings suggest that the additive effect of green tea, phytic acid and inositol may reduce the incidence of colon tumors, and can also be used as an adjuvant to chemomodulation.
The kinetics of thermal inactivation of peroxidase in butternut squash during water blanching was studied. Thin slices of squash were immersed in water at 60–90 °C for 0–60 min. For treatments below 70 °C, a biphasic, first-order kinetics model was proposed for peroxidase inactivation that would correspond to heat-labile and heat-resistant fractions of the enzyme. Parameters of the first-order model for the heat-labile and heat-resistant fractions were kL,ref=24.8733 min−1, EaL=14023 J/mol and kR,ref=0.0729 min−1, EaR=15794 J/mol, respectively. For treatments above 70 °C, a monophasic first-order kinetics model was proposed. Parameters were kref=8.6425 min−1, Ea=149900 J/mol. Decreases in ascorbic acid contents due to blanching were analyzed. Blanching processes at high temperature and short time resulted in higher ascorbic acid retention. A linear relationship between ascorbic acid retention and processing temperature was found.
Lactobacillus acidophilus ATCC 43121 were microencapsulated with sodium alginate by dropping method. The effects of microencapsulation on the changes in survival rate of the L. acidophilus ATCC 43121 during exposure to artificial gastrointestinal and on the change in heat susceptibility of L. acidophilus ATCC 43121 during the heat treatment were studied. In addition, cholesterol assimilation and intestinal adhesion of non-encapsulated and encapsulated L. acidophilus ATCC 43121 were also investigated to explore the effect of microencapsulation on health beneficial effect of lactic acid bacteria. Non-encapsulated cells were completely destroyed when exposed to artificial gastric juice (AGJ) of pH 1.2 and 1.5, while the treatment declined the viable count of encapsulated samples only by 3 log. Encapsulated cells exhibited a significantly higher resistance to artificial intestinal juice (AIJ) and heat treatment than non-encapsulated samples. The assimilative reductions of cholesterol by non-encapsulated and encapsulated L. acidophilus ATCC 43121 were 35.98% and 32.84%, respectively. However, encapsulation did not significantly (P>0.05) affect the adherence of L. acidophilus ATCC 43121 onto the human intestinal epithelial cell lines HT-29. The microencapsulation effectively protected the microorganisms from heat and acid treatment in delivering the viable cells to intestine without any significant adverse effect on their functionalities.
The chemical and quality characteristics of ‘Olinda’ and ‘Campbell’ oranges (nucellar budlines from Valencia late cultivar) were evaluated after exposure to a fruit core temperature of 44 °C and held at 44 °C for 100 min or 46 °C and held at 46 °C for 50 min, subsequent storage at 6 °C for 2 weeks and an additional week of simulated marketing period (SMP) at 20 °C. Exposure to either heat treatment caused neither visible damage nor fruit softening. Fruit weight loss rate in ‘Olinda’ oranges was unaffected by treatment but was higher than control fruit in heat exposed ‘Campbell’ oranges after storage, though at the end of SMP differences between treated and untreated fruit were non-significant. While neither heat treatment affected decay incidence in ‘Olinda’ oranges, significantly less decay was found in heat treated ‘Campbell’ fruit compared to control fruit both during storage and SMP.
The food-borne pathogens Listeria monocytogenes, Salmonella enterica, Staphylococcus aureus, Yersinia enterocolitica and Campylobacter jejuni, and the spoilage lactic acid bacteria (LAB), Escherichia coli and the yeast Debaryomyces hansenii were inoculated on slices of cooked ham, dry cured ham and marinated beef loin. During storage at 4 °C, L. monocytogenes and LAB increased up to 3.5 log units while the other species, unable to grow under refrigeration, continued at the spiking level. The application of a 600 MPa treatment effectively inactivated most of the microorganisms, the counts of which, except for LAB that increased in cooked ham and in beef loin, progressively decreased or maintained below the detection limit during the whole storage (120 days at 4 °C).
Solutions of a β-lactoglobulin isolate in water, in potassium phosphate buffer (20 or 50 mmol/L), and in pressure-resistant buffers, at a protein concentration of 25 g/kg and at pH 7.0, were processed at 150, 250, 350 or 450 MPa and 25 °C, for 15 min, then stored at 4 °C, usually for 24 h, before analysis. Bis-Tris (20 or 50 mmol/L) and bis-Tris-propane (10, 20 or 50 mmol/L) were selected as pressure-resistant buffers, while the pH of water or phosphate buffer is known to decrease reversibly by 0.2–0.3 pH unit per 100 MPa. After pressurization, nitrogen solubility at pH 4.7 and 7.0, and aggregation patterns by polyacrylamide gel electrophoresis were determined. Both indicated that aggregation of β-lactoglobulin was more extensive in pressure-resistant buffers than in phosphate buffer or in water. Electrophoretic patterns also revealed the progressive formation of dimers to hexamers and of higher polymers of β-lactoglobulin as a function of the type and molarity of buffer and of the pressure level. All high molecular weight aggregates and most oligomers disappeared when pressurized solutions were treated with β-mercaptoethanol (15 mL/L) prior to electrophoresis. Thus pressure induced the formation of intermolecular S-S bonds, especially when the pH was maintained close to neutral. Previous studies with thermally-induced β-lactoglobulin gels had shown that SH/ S-S interchange reactions were enhanced at or above neutrality.
It is established that acrylamide could be formed during heating of food products. In the present work we have studied whether the formed acrylamide could evaporate from food at elevated temperatures used in cooking (>160 °C) or used in determination of dry matter in laboratory analysis (ca. 105 °C). It was demonstrated that acrylamide evaporates from food samples during both cooking and temperatures used for drying. Up to ca. 4 μg/m3 could be measured above the fry pan during frying of potato. In parallel we have also studied whether acrylamide could be formed and evaporate during the elevated temperatures of 65–130 °C used for dry matter determinations in other types of samples containing biological material, like agricultural and environmental samples. It was found that acrylamide is formed during conditions for drying of soil, sediment and silage samples, as well as cereals, animal feed, etc. After drying, levels of acrylamide up to about 100 μg/kg were found, e.g. in samples of sediment and sludge. The measurements showed in the food, agricultural and environmental samples tested a minor fraction, roughly estimated to be 0.15–7.2% of the formed acrylamide evaporates at the used elevated temperatures.
An alternative freshness index method for abalone (Haliotis asinina) muscle packaged under atmospheric air (Air) and modified atmosphere (MA) of 40% CO2: 30% O2: 30% N2 packaging conditions and stored at 2 ± 1 °C was developed. Biochemical indices covering pH, total volatile basic nitrogen (TVB-N), trimethylamine (TMA) and nucleotide degradation products, as well as instrumental texture and color of the packaged abalones, were determined. Sensory characteristics including odor, color and appearance were evaluated and then summarized into overall freshness scores (freshness index). The biochemical and instrumental analyses were then calibrated with the freshness index, using an artificial neural network algorithm. The neural network was shown to be capable of correlating biochemical and instrumental analyses with the freshness index. A useful prediction was possible, as measured by a low mean square error (MSE = 0.092) and a regression coefficient (R2 = 0.98) between true and predicted data.
Momordica charantia Linn. var. abbreviata Ser. (Cucurbitaceae), also known as “Shan Ku Gua”, is a wild variety of bitter melon (BM) in Taiwan. The size of its fruits is only about one-fifth of the commonly seen BM. It is commonly consumed as vegetable and also used as a popular folk medicine. In this study, the antioxidant and free radical scavenging activities of BM aqueous (BM-H2O) and ethanol (BM-EtOH) extracts were evaluated using 2,2-diphenyl-1-picrylhydrazyl (DPPH), metal chelation, cytochrome c and xanthine oxidase inhibition (XOI) assays, as well as FeCl2-ascorbic acid induced lipid peroxidation (thiobarbituric acid reactive substances, TBARS) assay in rat liver homogenates in vitro. Total flavonoid and phenol contents of BM extracts were also analyzed. Results showed that both BM-H2O (IC50=129.94 μg/ml) and BM-EtOH (IC50=156.78 μg/ml) possess potent DPPH radical scavenging activity, which was better than vitamin E (IC50=172.21 μg/ml). These extracts also showed better iron chelating activity than vitamin E. However, they were weaker than vitamin E in free radical scavenging, xanthine oxidase inhibitory and anti-lipid peroxidation activities. With the exception of XOI activity [IC50=7.90 μg/ml (BM-H2O) vs. 7.69 μg/ml (BM-EtOH)], BM-H2O showed a lower IC50 value in free radical scavenging [IC50=6.15 μg/ml (BM-H2O) vs. 7.08 μg/ml (BM-EtOH)] and anti-lipid peroxidation [IC50=53.72 μg/ml (BM-H2O) vs. 88.51 μg/ml (BM-EtOH) for liver; 82.53 μg/ml (BM-H2O) vs. 91.83 μg/ml (BM-EtOH) for brain] activities than BM-EtOH. Both BM extracts showed a weak anti-lipid peroxidation activity in plasma. BM-H2O (62.0 mg/g) possessed a significant higher concentration of total flavonoids than BM-EtOH (44.0 mg/g), but was lower in the total phenol content (BM-H2O: 51.6 mg/g vs. BM-EtOH: 68.8 mg/g). In conclusion, BM extracts possess potent antioxidant and free radical scavenging activities. These antioxidant activities could have contributed, at least partly, to the therapeutic benefits of the certain traditional claims of wild BM.
An, the Japanese equivalent of bean paste, is conventionally prepared by mashing whole cooked beans and removing the seed coats. An granules processed from raw azuki beans with 1 sec of abrasion, 2 sec of abrasion or a grinding treatment prior to cooking were compared to an granules processed from raw whole beans. The effects on the microstructure of an granules of increasing the cooking time from 30 to 45 min for beans pretreated with 1 sec of abrasion, or from 85 to 120 min for whole beans were also examined. Freeze dried an granules processed from beans abraded for 1 or 2 sec, or whole beans, were intact. Freeze dried an granules processed from ground beans exhibited ruptured cell walls. Freeze dried an granules also exhibited damaged cell walls when the cooking times during the an process were increased. The starch gelatinization enthalpies determined by differential scanning calorimetry for an processed from whole beans, from beans pretreated by abrasion or grinding, or with the increased cooking times were 45–54% of the starch gelatinization enthalpy determined for raw azuki bean cotyledon flours.
To investigate the effects of high atmospheric O2 on berry drop in ‘Kyoho’ grapes (Vitis vinifera X V. labrusca), changes in fruit detachment force (FDF), berry abscission and enzyme activities in the abscission zone (AZ) were examined during 60 days of storage in air (control), 40% O2+30% CO2 or 80% O2 at 0 °C and 95% relative humidity. There was a high negative correlation between FDF and berry drop. Cellulase activity increased over time and correlated strongly with berry abscission. Polygalacturonase (PG) activity increased markedly for the first 30 days and then decreased slightly. Pectinesterase (PE) maintained a basal level of activity at low temperatures. Cellulase, PG and PE activities were the lowest in fruits in 80% O2, followed by 40% O2+30% CO2 and air storage. Peroxidase (POD) activity dropped firstly and subsequently rose sharply, which promoted by 80% O2 and inhibited by 40% O2+30% CO2 compared with control. High O2 suppressed the activities of cellulase, PG and PE, maintained higher FDF, and reduced berry abscission during storage.
The present study investigated the effect of active packaging, nitrogen flushing, container oxygen barrier and storage conditions on quality retention of raw whole unpeeled almonds. Almond kernels were packaged in: a) polyethylene terephthalate//low-density polyethylene (PET//LDPE), and b) low-density polyethylene/ethylene vinyl alcohol/low-density polyethylene (LDPE/EVOH/LDPE) pouches under N2, with or without an oxygen absorber, heat-sealed and stored for a period of 12 months. Quality parameters monitored were: peroxide value (PV), hexanal content, color, fatty acid composition and volatile compounds. PV ranged between 0.17 for fresh almonds and 9.22 meq O2/kg oil for almonds packaged in PET//LDPE pouches under N2 exposed to light at 20 °C after 12 months of storage. Respective values for hexanal were <28.5 μg/kg and 4.88 mg/kg. Polyunsaturated fatty acids (PUFA) and saturated fatty acids (SFA) increased with a parallel decrease of monounsaturated fatty acids (MFA) after 12 months of storage in all treatments. Likewise, volatile compounds such as aldehydes, ketones, alcohols, alkanes and aromatic hydrocarbons increased indicating enhanced lipid oxidation. Color was the parameter least affected. Use of the oxygen absorber provided a shelf life of at least 12 months for all samples irrespective of container oxygen barrier, lighting conditions and storage temperature.
Psyllium husks were treated with commercial food grade enzymes under solid-state reaction conditions to improve their water-absorbing and gelling properties. The modified psyllium preparations were analyzed and compared to the original psyllium and the control, treated with no enzyme under the same reaction condition, for their water-absorbing ability, gelling capacity, surface structures, and fiber contents. The results showed that the solid-state enzymatic modification was able to reduce both water-absorbing and gelling abilities of psyllium with a slight reduction in soluble fiber content. Scanning electron microscopy measurements showed that the enzymatic modification decreased the total surface area. This may contribute to the reduced water-absorbing ability of the modified psyllium. The solid-state enzymatic procedure requires neither special equipment nor additional steps to remove moisture after inactivating the enzymes and generates no chemical waste. This study demonstrated the potential of preparing novel psyllium preparations with improved gelling and water-absorbing properties using a solid-state enzymatic method for commercial food applications.
In the present study, water absorption capacity (WAC) and the resulting baking performance of different barley–wheat flour blends were investigated by baking breads containing 40% barley flour. The different barley varieties varied in polysaccharide contents and composition. Knowledge about variations in WAC and its possible effects on the baking performance were gained by choosing a constant water addition. These variations were related to differences in chemical content and composition. Large variations in WAC were observed for the different barley–wheat mixtures. These variations further resulted in variations in weight, volume and form ratio of the breads. Thus, large individual differences in baking performance were observed and these differences related to differences in polysaccharide content and composition of the different barley flours. Total β-glucan content was the most important parameter for the baking performance and hence, the bread quality due to its significant contribution to the WAC.
Fish oils (FO) and their ethyl ester derivatives (EE) are proposed as rich sources of n -3 polyunsaturated fatty acids (PUFA), in view of their nutritional and therapeutic effects. However, they have drawbacks due to their high degree of susceptibility to oxidation, both during manufacturing and in living organisms. We prepared wax esters (WE) by transesterification of stoichiometric amounts of ethyl esters enriched with n -3 PUFA and long-chain alcohols (18–22 carbon atoms). They are waxy solids, with melting points from 30 to 52 °C, depending on the degree of unsaturation in the acidic and alcoholic moieties of the molecules. We studied their bioavailability in comparison with commercially available products, namely EE and FO, using an animal model (rat). WE have a low degree of susceptibility to oxidation and a high degree of enzymatic hydrolysis in vitro. After an oral load, rats hydrolyse and absorb WE to a greater extent than EE, resulting in significant enrichment of n -3 PUFA in plasma triglycerides. After dietary supplementation with WE (0.15 g/d/rat) for 4 weeks, n -3 PUFA in plasma phospholipid were comparable to those of rats receiving diets supplemented with FO and EE in equimolar concentrations of n -3 PUFA. Body weight, lipid profile and intestinal transit were not affected by 4 weeks' treatment with WE. These formulations offer a potential advantage as food supplements over products in current use, on account of their greater stability.
This study evaluated the correlation between optical density as measured by absorption photometry, water-insoluble solids (WIS) and consistency as measured by the Bostwick consistometer for a variety of concentrated tomato products. Linear regression analysis indicated a linear correlation (R2=0.97) between optical density and WIS content in diluted tomato paste, a linear correlation (R2⩾0.92) between optical density and consistency in various commercial tomato products and a linear correlation (R2=0.93) between optical density and consistency during commercial production of tomato puree made from ripe tomatoes. The optical density appeared to be unaffected by product temperature and flow rate. Potential limitations of in-line absorption photometry to monitor and control tomato product consistency are briefly discussed.
Potential effects of the insoluble fiber-rich fractions (IFRF) prepared from carrot pomace on lipid and cholesterol absorption in hamsters were investigated. As compared with the cellulose-added and fiber-free diets, IFRF diet significantly (P<0.05) lowered the levels of serum triglyceride, serum total cholesterol, and liver cholesterol, and meanwhile resulted in a significantly (P<0.05) higher HDL:total cholesterol ratio as well as higher levels of fecal lipids, cholesterol, and bile acids. Significant correlations were observed among the levels of serum triglyceride, serum total cholesterol, liver cholesterol, fecal lipids, fecal cholesterol, and fecal bile acids, implying that the hypolipidemic and hypocholesterolemic effects of IFRF were partly attributed to the reduced absorption of lipid and cholesterol. Our results suggested that IFRF could be a potential functional ingredient in the fiber-rich diets for controlling serum cholesterol concentration.
Direct thiolysis of crude plant materials and HPLC analysis of the reaction media were used to quantify and to characterise procyanidins (condensed tanins) and other main polyphenols of three dessert apple varieties. Results showed evidence of the large predominance of the procyanidin class in the polyphenolic composition of dessert apple skin and flesh. The structure of procyanidins was wholly homogeneous with (-)-epicatechin representing more than 95% of the constitutive flavan-3-ol units and with average degrees of polymerisation in the 5–7 range.
Niger (Guizotia abyssinica Cass.) seeds were extracted with chloroform/methnol (2:1, v/v) and total lipid content was 49.9% of seed weight. The major fatty acid was linoleic acid followed by oleic acid as a second unsaturated fatty acid. Palmitic acid was the major saturated fatty acid followed by stearic acid. Column chromatography with solvent of increasing polarity yielded 93.0% neutral lipids, 4.90% glycolipids and 0.60% phospholipids (PL). Polar lipids were characterized by higher palmitic acid and lower linoleic acid levels. PL subclasses were separated via high-performance liquid chromatography (HPLC). The major individual PL subclasses were found to be phosphatidylcholine followed by phosphatidylethanolamine, phosphatidylinositol and phosphatidylserine, respectively. Phosphatidylglycerol and lysophosphatidylcholine, on the other hand, were detected in smaller quantities. The predominant PL-bound fatty acids presented were linoleic, palmitic and oleic acids.
Probiotic microorganisms were incorporated into a nonfermented, vegetarian frozen soy dessert at initial populations greater than 106 cfu/g. The product was assessed for the survival of probiotic microorganisms and sensory acceptability. Lactobacillus acidophilus MJLA1, L. rhamnosus 100-C, L. paracasei ssp. paracasei 01, Bifidobacterium lactis BBDB2, B. lactis BB-12 all survived the 6 month storage trial at populations of 107 cfu/g or greater. Saccharomyces boulardii 74012 did not retain sufficient viability, decreasing below the desirable level of 106 cfu/g. To detect sensory differences, product containing L. acidophilus MJLA1, S. boulardii 74012 and an uninoculated control were stored for 0, 4 and 7 months and compared using triangle tests. Product inoculated with L. acidophilus MJLA1 could not be distinguished from the control sample. Product with S. boulardii 74012 differed from the control and L. acidophilus MJLA1 and developed undesirable flavours during storage. The frozen soy dessert was a suitable food for the delivery of bacterial probiotic strains with excellent viability and acceptable sensory characteristics.
Optimization of a chocolate-flavored, peanut–soy beverage was done using response surface methodology (RSM). Twenty-eight beverage formulations were processed by mixing three basic ingredients: peanut (X1=30.6 g/100 g–58.7 g/100 g), soy (X2=28.3 g/100 g–43.5 g/100 g), and chocolate syrup (X3=13.0 g/100 g–25.9 g/100 g). The proportions of these ingredients were obtained using a three component, constrained mixture design where the source of soy was either flour (SF) or protein isolate (SPI). Consumer acceptability was measured in terms of nine response variables by 41 consumers using a 9-point hedonic scale. Parameter estimates were determined by performing regression analysis with no intercept option. l-pseudo-components were introduced to get equivalent second degree models further used to generate contour plots. The regions of maximum consumer acceptability [hedonic rating ⩾5.0 since the control (commercial chocolate milk) ratings were 6.0–7.0] were identified and marked on these contour plots for each sensory response. Superimposition of contour plots corresponding to each response variable resulted in optimum regions having consumer acceptability ratings ⩾5.0. Optimum formulations were all the combinations of X1: 34.1 g/100 g–45.5 g/100 g, X2: 31.2 g/100 g–42.9 g/100 g, and X3: 22.4 g/100 g–24.1 g/100 g for SF-based; and X1: 35.8 g/100 g–47.6 g/100 g, X2: 31.2 g/100 g–43.5 g/100 g, and X3: 18.3 g/100 g–23.6 g/100 g for SPI-based beverage formulations.
Consumer acceptance and intensity ratings of roasted peanuts stored at temperatures of 23, 30, 35, and 40 °C, and water activities (aw) of 0.33, 0.44, 0.54, 0.67 and 0.75 were determined over time. Consumer acceptance ratings, including overall, appearance, color, and texture were affected by storage water activity and time, but not by storage temperature. Consumer intensity ratings of crunchiness were affected by storage water activity and time, but not storage temperature. Aroma acceptance, flavor acceptance, and roasted peanutty and stale/oxidized/rancid intensity ratings of roasted peanuts were dependent on storage temperature, water activity and time.Shelf-life of roasted peanuts was predicted by all consumer attributes (R2>0.60) and was best predicted by aroma acceptance (R2=0.75). Using contour plots with ratings >5.0 for all acceptance attributes, the shelf-life of roasted peanuts stored at 23 °C and between 0.33 and 0.75 aw was limited by overall acceptance and decreased by approximately 50% with each 0.1 aw increase. At accelerated temperatures of 30, 35 and 40 °C, shelf-life of roasted peanuts was predominantly limited by flavor acceptance (>5.0), and to a lesser extent by overall acceptance (>5.0). Shelf-life of roasted peanuts stored at accelerated temperatures decreased by 50% or more with each 0.1 aw increase.
Consumer awareness and acceptance, and influence of benefit statements and price on acceptance of irradiated foods were investigated in Turkey. Consumer awareness of food irradiation was very low (29%). Majority of consumers (80%) were uncertain about the safety of irradiated foods. Only 11% expressed irradiated foods are safe. Level of positive attitude towards irradiated foods increased substantially (62%) upon hearing a benefit statement of food irradiation. Purchase intent of irradiated foods was highest (44%) when price is same as unirradiated foods, but significant proportion of consumers indicated to pay 5% premium price for irradiated foods. A successful market for irradiated foods can be achieved by educating consumers with the benefit and uses of irradiation process.
Pasta is a staple food in many countries. Amaranth is a pseudo-cereal being re-discovered because of its nutritional properties. The main objective of this study was to evaluate the potential of the green material of the amaranth plant (leaves) as a component for pasta production and its effect on the pasta quality and consumer acceptance. Dried amaranth (Amaranthus caudatus) leaves and spinach leaves flours were prepared. Pasta samples were manufactured following a small-scale pilot procedure. Amaranth pasta samples were evaluated for its chemical composition, cooking quality, textural, and sensory/consumer acceptance. Results showed that pasta made with dried amaranth leaves had similar chemical composition (protein content: 14.18 g/100 g, Fe content: 9.1 mg/100 g), cooking quality (2.15 pasta weight increase, 4.47% residue loss), textural characteristics (firmness and adhesiveness), and sensory acceptance than green pasta made with dried spinach leaves. Since amaranth leaves have similar nutritional characteristics to spinach leaves and since this biomass in not currently used for food purposes, this study points out that amaranth leaves could be technically used for pasta production and that consumer acceptance of pasta made with amaranth green leaves flour is similar to that of pasta made with spinach.
Acrolein can be at the origin of an important organoleptic defect in beverages made from apples. Its content was investigated in freshly distilled Calvados and cider. The specificity of 3-methylbenzothiazolone hydrazine (MBTH) towards carbonyl compounds was used in order to derive acrolein in azines. Azines were separated and detected by gas chromatography coupled with a nitrogen–phosphorus Detector. Results showed that acrolein concentrations could be quickly determined in either Calvados or cider. Accuracy of quantification was better than 6% for concentrations about 1 mg/l in freshly distilled Calvados and 10% for concentrations about 10 μg/l in ciders. Acrolein content was found between 0.7 and 5.2 mg/l in samples of freshly distilled Calvados whereas it was between 7 and 15 μg/l in samples of cider. This method of quantification was applied to study disappearance kinetics of acrolein in cider. Acrolein content was found to decrease rapidly during the first hours and to change very slowly after a few days. Its behaviour during a distillation was also investigated showing that in spite of its high volatility it could also be found in the last fractions of distillation.
Soy whey is a rich by-product of tofu-manufacturing industries. We have previously optimized the growth of Lactobacillus acidophilus FTCC 0291 in soy whey upon supplementation of meat extract, vegetable extract and peptone using response surface methodology (RSM). The present study evaluated the proteolytic and angiotensin-I converting enzyme (ACE)-inhibitory activities of L. acidophilus FTCC 0291 in the optimized soy whey medium. The probiotic-fermented soy whey exhibited growth-associated proteolysis and ACE-inhibitory activity. Proteolysis was highly correlated with ACE-inhibitory activity, indicating that peptides liberated via fermentation may have exerted in vitro antihypertensive properties. Of the three nitrogen sources studied, peptone was found to have the highest influence on growth performance and ACE-inhibitory activity. Our results strongly indicated that probiotic-fermented soy whey produced in vitro antihypertensive bioactivity, and hence could be further developed into a carrier for probiotics with enhanced functional properties.
This study examined the influence of Raftiline HP®, added at the rate of 1, 2 and 3 g 100 mL−1 to reconstituted skim milk, on the growth and biochemical activities of selected strains of Streptococcus thermophilus, Lactobacillus delbrueckii ssp. bulgaricus, Lactobacillus casei, Lactobacillus acidophilus and Bifidobacterium longum. The growth of B. longum and S. thermophilus was improved in reconstituted skim milk (RSM) containing 1 g 100 mL−1 Raftiline HP®. All the organisms except for S. thermophilus produced more lactic acid and acetic acid in the presence of Raftiline HP® than in the control. L. acidophilus and B. longum showed improvement in the proteolytic capabilities at all the three levels of Raftiline HP® addition. L. delbrueckii ssp. bulgaricus showed maximum percent ACE inhibition in RSM containing 2 g 100 mL−1 Raftiline HP® while B. longum exhibited this potential in RSM containing 3 g 100 mL−1 Raftiline HP®. All organisms, except L. delbrueckii ssp. bulgaricus, however, showed improvement in the α-glucosidase inhibitory activity in RSM containing Raftiline HP®.
A trout diet was supplemented with 0, 8.5, or 15 g/100 g of flaxseed oil (FO). To prevent lipid oxidation of fillets, FO-supplemented diets were also enhanced with 0, 400, and 900 mg/kg of alpha-tocopheryl acetate (α-TA). Total fat, moisture content, lipid oxidation, fatty acid profile, and α-tocopherol content of fillets were determined following fish harvest on days 0, 30, 60, 90, and 120. FO supplementation resulted in increased (P<0.05) concentration of omega-3 fatty acid (ω3 FA) in fillets, mainly due almost two-fold increase (P<0.05) of α-linolenic acid, while docosahexaenoic and eicopentaenoic acids slightly decreased (P<0.05). Regardless of supplementing trout diets with FO or α-TA, no (P>0.05) difference of the total fat in fillets was measured. The highest (P<0.05) α-tocopherol content in fillets was determined when supplementing trout with 900 mg/kg of α-TA at day 120. The effect of retarding lipid oxidation in fillets was recorded after supplementing trout with α-TA for 60 days. Our results indicate that regardless of FO level in trout diet, 900 mg/kg of α-TA can prevent lipid deterioration of fillets. However, to achieve more pronounced antioxidant effect in the ω-3-enhanced trout fillets, a synergetic effect of antioxidants and anaerobic packaging with α-TA supplementation should be investigated.
Twenty-four 12-week-old female turkeys divided into four equal groups were fed a basal diet (CONT) or basal diet supplemented with 300 mg α-tocopheryl acetate/kg (TOC), or 5 g rosemary/kg (ROS5), or 10 g rosemary/kg (ROS10), for 4 weeks. Following slaughter, fillets from breast were stored at 4 °C in the dark for 12 days, and lipid oxidation was assessed on the basis of the malondialdehyde formed, whereas microbial growth on the basis of total viable counts (TVC), lactic acid bacteria (LAB), Enterobacteriaceae (ENB) and psychrotrophic (PSY) bacteria. Results showed that incorporation of dried rosemary in turkey diets delayed lipid oxidation in raw breast meat during refrigerated storage. Dietary rosemary at the level of 1 g/100 g was significantly (P<0.05) more effective in delaying lipid oxidation compared to 0.5 g/100 g but inferior to the dietary supplementation of 300 mg α-tocopheryl acetate/kg. TVC, LAB, ENB and PSY bacterial counts were all significantly increased (P<0.05) in breast samples of all groups throughout the refrigerated storage. The TOC and CONT groups presented TVC, LAB, ENB and PSY counts that did not differ (P>0.05) among each other, during the whole storage period. However, the rosemary-supplemented groups presented bacterial counts that were significantly lower (P<0.05) than the CONT and TOC groups, at day 2 of storage period and thereafter. During this period, the ROS5 group presented TVC, LAB, ENB and PSY counts that were significantly higher (P<0.05) than the ROS10 group.
Eleven red wines imported from foreign country and 40 domestic fruit wines, including 15 red wines, 4 white wines, 7 plum wines, and 14 other fruit wines, sold in the supermarkets in Taiwan were purchased and tested to determine the occurrence of biogenic amines and histamine-forming bacteria. The levels of pH, total soluble solids (TSS), titratable acidity (TA), reducing sugar (RS), total sugar (TS), sulphites, methanol (milligram per liter of pure ethanol), ethanol and Pb in all samples ranged from 3.0 to 4.1, 6.8 to 24.4 °Brix, 0.3 to 1.7 g/100 mL, 0.2 to 17.6 g/100 mL, 1.6 to 28.4 g/100 mL, <2 to 260.5 mg/L, <1 to 2559 mg/L, 5.0 to 15.6 g/100 mL and <1 to 46.2 μg/L, respectively. The levels of TSS, TA, RS, and TS in plum wine samples were significantly higher than those of the other wines samples, whereas the pH value in plum wine samples was lower than that of the other wines samples. The average content for each of the nine biogenic amines in all samples was less than 5.2 mg/L. However, higher levels of histamine and spermine were detected in domestic fruit wine samples than the imported red wine samples. Five histamine-forming isolates isolated from domestic red wine and jackfruit wine, capable of producing 13.0 mg/L to 69.1 mg/L of histamine in trypticase soy broth (TSB) supplemented with 2 g/100 mL l-histidine (TSBH) or MRS broth supplemented with 2 g/100 mL l-histidine (MRSH), were identified as Bacillus pumilus (one strain), Bacillus sp. (two strains) and Acetobacter pasteurianus (one strain) by 16S rDNA sequencing with PCR amplification, and Zygoascus hellenicus var. hellenicus (one strain) by internal transcribed spacer sequencing with PCR amplification. To our knowledge, this is the first report to demonstrate the occurrence of histamine-forming bacilli bacteria, acetic bacteria and yeast in fruit wine.
Effects of gamma irradiation on the color characteristic and biological activities of methanol and acetone extracts of Lonicera japonica (Japanese honeysuckle) irradiated at 0, 10, 20, and 30 kGy were investigated. Hunter color L*- and a*-value increased by irradiation in a dose-dependent manner, resulting in it being lighter than the nonirradiated, while Hunter color b*-values decreased by irradiation (P<0.05). The extracts from L. japonica showed an inhibition effect against tyrosinase, xanthine oxidase and the nitrite scavenging ability. Tyrosinase inhibition effect of L. japonica was higher in the irradiated sample than the nonirradiated, and the effect was increased by irradiation doses. The L. japonica extracts had a higher inhibitory effect against xanthine oxidase, and the effect was not changed by irradiation. Nitrite scavenging activity was the highest in L. japonica extract at pH 1.2. The difference between solvents used was not detected. Thus, gamma irradiation may have no influence on the biological activities of the L. japonica extracts except for the tyrosinase inhibition effect when irradiated up to 30 kGy.
Top-cited authors
Wendy Brand-Williams
  • French National Institute for Agriculture, Food, and Environment (INRAE)
Marie-Elisabeth Cuvelier
  • AgroParisTech, centre de Massy, France
Min Zhang
Soottawat Benjakul
  • Prince of Songkla University
Jong-Whan Rhim
  • Kyung Hee University