RESUMO
There is an increasing demand for non-dairy probiotic food due to the constraints associated with dairy probiotics. In this study, a co-culture synbiotic beverage was prepared using a mixture of mung bean and rye sprouts inoculated with Lactobacillus plantarum (B-28) and Lactobacillus casei (B-29), along with inulin and oligofructose as prebiotics. The effects of prebiotic addition and starter culture on the survival of probiotics during cold storage and simulated gastric conditions were examined. Additionally, titratable acidity, pH, phenolic content, antioxidant activity, and sensory characteristics were evaluated over a 28-day period. The resulting product demonstrated good survival for L. casei (107 CFU.ml-1) and L. plantarum (106 CFU.ml-1) after 4 weeks under refrigeration with no significant changes in quality. The samples exhibited significantly high total phenolic content (TPC), ranging from 19.18 to 25.75 mg GAE/100 mL, which L. casei-containing drinks exhibited the highest TPC activity (p < 0.05). All treatments showed a significant reduction in probiotic survival during gastrointestinal digestion in the laboratory conditions (p < 0.05), although more than 50% survival was observed for all strains. The addition of prebiotics to the beverages led to a significant decrease in phenolic content (p < 0.05), but improved sensory scores. The highest turbidity was observed in the sample containing both probiotics and inulin on the 28th day at 38.1 (NTU). In general, the synergistic effect of probiotics was more pronounced when used together with both prebiotics in the beverages compared to their individual use. The results suggest that the production of this beverage could serve as a nutritious alternative to lactose-sensitive dairy beverages and contribute to the development of future probiotic food products.
Assuntos
Vigna , Antioxidantes , Secale , Prebióticos , Inulina , Bebidas , FenóisRESUMO
BACKGROUND: The adulteration of milk by hazardous chemicals like surfactants has recently increased. It conceals the quality of the product to gain profit. As milk and milk-based products are consumed by many people, novel analytical procedures are needed to detect these adulterants. This study focused on Fourier-transform infrared (FTIR) spectroscopy equipped with an attenuated total reflection (ATR) accessory, and near-infrared (NIR) spectroscopy for the determination of milk-surfactant adulteration using a genetic algorithm (GA) coupled with multivariate methods. The model surfactant was sodium dodecyl sulfate (SDS), and its concentration varied from 1.94-19.4 gkg-1 in adulterated samples. RESULTS: Prominent peaks in the spectral range of 5500-6400 cm-1 , 1160-1260 cm-1 and 1049-1080 cm-1 may correspond to the sulfonate group in SDS. A genetic algorithm could significantly reduce the number of variables to almost one third by selecting the specific wavenumber region. Principal component analysis (PCA) for ATR and NIR data indicated separate clusters of samples in terms of the concentration level of SDS (P ≤ 0.05). Partial least squares regression (PLSR) was used to determine the maximum R2 value for ATR and NIR data for calibration, cross-validation and prediction, which were 0.980, 0.972, 0.980, and 0.970, 0.937, and 0.956 respectively. The results showed apparent differences between unadulterated and adulterated samples using partial least squares-discriminant analysis (PLS-DA), which was validated by the permutation test. CONCLUSION: The results clearly show the successful application of the proposed methods with multivariate analysis in the selection of variables, classification, clustering, and identification of the adulterant in amounts as low as 1.94 gkg-1 in milk. © 2020 Society of Chemical Industry.
Assuntos
Contaminação de Alimentos/análise , Leite/química , Espectroscopia de Infravermelho com Transformada de Fourier/métodos , Tensoativos/análise , Algoritmos , Animais , Bovinos , Análise Discriminante , Análise dos Mínimos Quadrados , Dodecilsulfato de Sódio/análiseRESUMO
Infrared-vacuum dehydration characteristics of pumpkin (Cucurbita moschata) were evaluated in a combined dryer system. The effects of drying parameters, infrared radiation power (204-272 W), system pressure (5-15 kPa), slice thickness (5 and 7 mm) and time (0-220 min) on the drying kinetics and characteristics of pumpkin slices were investigated. The vacuum pressure, lamp power and slice had significant effect on the drying kinetics and various qualities of the dried pumpkin. Moisture ratios were fitted to 10 different mathematical equations using nonlinear regression analysis. The quadratic equation satisfactorily described the drying behavior of pumpkin slices with the highest r value and the lowest SE values. The effective moisture diffusivity increased with power and ranged between 0.71 and 2.86 × 10(-9) m(2)/s. With increasing in infrared radiation power from 204 to 272 W, ß-carotene content of dried pumpkins decreased from 30.04 to 24.55 mg/100 g. The rise in infrared power has a negative effect on the color changes (ΔE). The optimum condition was determined as power, 238W, pressure, 5 kPa and slice thickness, 5mm. These conditions resulted into dried pumpkin slices with maximum B-carotene retention.
RESUMO
During the frying of foods, undesirable reactions such as protein denaturation, acrylamide formation, and so on occur in the product, which has confirmed carcinogenic effects. The use of antioxidants has been proposed as an effective solution to reduce the formation of these compounds during the process. The current study aimed to assess the impact of an edible coating holding within chia seed gum (CSG) and Rosa canina L. extract (RCE) nanoemulsions on the physicochemical properties, oil uptake, acrylamide formation, 5-hydroxymethyl-2-furfural (HMF) content, and sensory characteristics of beef-turkey burgers. The RCE-loaded nanoemulsions were prepared using the ultrasonic homogenization method, and different concentrations (i.e., 10%, 20%, and 40% w/w) were added to the CSG solutions; these active coatings were used to cover the burgers. CSG-based coatings, especially coatings containing the highest concentration of nanoemulsions (40%), caused a significant decrease in the oil uptake and moisture retention, acrylamide content, and HMF content of fried burgers. The texture of coated burgers was softer than that of uncoated samples; they also had a higher color brightness and a lower browning index. Field emission scanning electron microscopy analysis showed that RCE concentration less than 40% should be used in CSG coatings because it will cause minor cracks, which is an obvious possibility of failure of coating performance. Coating significantly (4-10 times) increased the antioxidant activity of burgers compared to the control. In conclusion, it is suggested to use the active coating produced in this study to improve fried burger quality and modulate acrylamide formation.
Assuntos
Acrilamida , Produtos da Carne , Animais , Bovinos , Acrilamida/análise , Antioxidantes/química , Produtos da Carne/análiseRESUMO
The current trend in the production of smart films involves the use of pH-responsive color indicators derived from natural sources. In line with this trend, the aim of this research is to produce edible films from sodium alginate (A) and chitosan (Ch) incorporating red beet anthocyanin (Ac) extract, and to assess the properties of these films and their use as coatings for chicken fillets. The study employed a factorial design to evaluate the effects of treatments C (control), A25%-ch75% (films consisting of 25% sodium alginate and 75% chitosan), and A25%-ch75%-Ac (films consisting of 25% sodium alginate, 75% chitosan, and red beet anthocyanin). The findings indicate that the inclusion of red beet anthocyanin extract did not result in any discernible differences in the FTIR spectra of the film samples. Analysis of the XRD results revealed that the addition of the extract led to a reduction in the crystal structure of the film. Moreover, SEM results demonstrated that the extract caused alterations in the polymer chains and an increase in the porosity of the film matrix. With regard to the chicken fillet samples coated with the film, over time, there was an increase in microbial analysis (total microorganism count and Staphylococcus aureus coagulase-positive) and chemical properties (pH, peroxide, thiobarbituric acid, and nitrogen compounds) for all samples. However, this trend was significantly lower in the samples coated with the Ac extract (P < 0.05). Texture analysis results revealed that the hardness parameter of all samples decreased over the storage period, while the samples containing the Ac extract demonstrated a significant increase in this parameter (P < 0.05). Additionally, the color changes of the pH sensor corresponded to the anthocyanin structure. Based on the results, the smart film composed of sodium alginate/chitosan incorporating red beet anthocyanin extract has the potential to enhance the quality, prolong the shelf life, and decrease the microbial load of chicken fillet when used as a coating. Furthermore, red beet anthocyanin can serve as a suitable indicator for spoilage changes in packaged food products.
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The aim of this study was to evaluate the characteristics of dually modified sago starch by acid hydrolysis (AH)-hydroxypropylation (HP). For this purpose, sago starch was modified with the combination by AH (5-20 h hydrolysis times) followed by HP (5%-25% ratio of propylene oxide) processes. The results showed that the dual modification of the sago starch structure didn't have a significant effect on the size of starch granules, and the granule size was in the range of 0.005-0.151 µm; however, the pasting properties and the glass transition temperature decreased significantly (p < .05). Increasing the level of propylene oxide from 5% to 25% caused a significant increase in the substitution degree (DS) and swelling ability of starches and reduced the syneresis, while with increasing acid hydrolysis time from 5 h to 20 h, starch swelling decreased and syneresis increased (p < .05). AH process at high hydrolysis times (20 h) increased the gelatinization temperatures and decreased retrogradation temperatures. Increasing the level of propylene oxide in both single and dual modification reduced the temperatures and enthalpy of gelatinization and retrogradation of sago starch. In summary, dually modified sago starch has a great potential to use in specific food products such as frozen dough or frozen bakery products.
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The food and water contamination with heavy metals is increasing due to the environmental pollutions. Lead and cadmium are the toxic heavy metals for humans that can be found in air, soil, water, and even food. Lactic acid bacteria have the ability to remove and diminish the level of heavy metals. In this study, Lactobacillus acidophilus was used to remove lead and cadmium in milk and the capability of this valuable bacterium in biosorption of these metals low concentrations (µg/L or ppb) in milk was evaluated. First, the variables on lead and cadmium removal by this bacterium have been studied by Plackett-Burman design. Then, the bioremoval process was optimized and the three main factors, the bacterium concentration, contact time, and the initial heavy metal concentration were chosen by using a central composite design. The optimum lead and cadmium bioremoval yield of 80% and 75% were observed, respectively, at 1 × 1012 CFU of L. acidophilus in milk at the 4th day and the initial ion concentration of 100 µg/L. The 3D plots analysis showed the interaction effects on metal biosorption. This study showed that L. acidophilus is a natural effective biosorbent for lead and cadmium removal from milk.