da Silva, Cristiane de Bonade Menezes, Cristiano Ragagninda Rosa, Claudia Severoda Rosa, Jessica Righi...
8页
查看更多>>摘要：This study evaluated the anthocyanin stability and the formation characteristics of microencapsulated blueberry extract produced by a spray-drying method using maltodextrin DE20 and hi-maize wall materials as the standard formulation (S); the other treatments were combined with inulin (T1), gum arabic (T2), and inulin and gum arabic (T3). The characteristics of microcapsule formation and the stability were evaluated at different storage temperatures during 60 days of analysis. The microcapsules showed encapsulation efficiency that ranged from 96.80 to 98.83%. Of all the treatments, T3 presented the lowest anthocyanin loss at all the storage conditions (5.94% at room temperature, 5.82% at refrigeration, and 4.45% at freezing temperature) and, the longest half-life (679.81 days at room temperature, 693.32 days at refrigeration, and 913.41 days at freezing temperature). The combination of wall materials resulted in substantially improved stability, as well as the protection of anthocyanin compounds under the simulated gastrointestinal conditions, which was possibly due to synergistic action. These results are important findings regarding the preservation and increased shelf-life of anthocyanin compounds, given the instability of these compounds, and they increase the possibility of using them as functional ingredients by the food industry.
查看更多>>摘要：In this paper, prepared alkali-induced egg white gel (EWG) was treated at different temperatures (100-121 degrees C) to explore the hydration mechanism under high temperatures (>= 100 degrees C). The physicochemical, mechanical and rheological properties and intermolecular interactions of the EWG were investigated. Results showed that with increasing temperature the pH, free alkalinity and surface hydrophobicity of EWG increased initially but then decreased, together with gel hydration, and the browning intensity increased markedly. The mechanical properties, including hardness, puncture strength and springiness, rheological characteristics-determined via apparent viscosity and frequency sweep results-and water-holding capacity significantly decreased as temperature increased. Fourier-transform infrared (FTIR) spectroscopy revealed that the beta-sheet contents decreased significantly, and the a-helical and beta-turn contents improved markedly with increasing temperature. The protein fraction results showed that hydrogen bonds, hydrophobic interactions and disulphide bonds were destroyed in the heating process. This study provides deep insights into EWG destruction under high temperature and the relationship with intermolecular interactions, enabling control over EWG quality.
da Silva, Suellen Paulado Valle, Anita FerreiraPerrone, Daniel
7页
查看更多>>摘要：The aim of this study was to develop nutritionally enriched and sensorially well-accepted biscuits by incorporating spray-dried microencapsulated S. maxima biomass. Spirulina biomass presented high iron (49.8 mg/100 g) and protein contents (80.0%) with high biological value (chemical score > 99%). Spirulina biomass lipids presented high unsaturated/saturated fatty acids ratio (0.7) and a high content of polyunsaturated fatty acids (32.7%), with an emphasis on gamma-linolenic acid (13.8%). No more than 10% of non-microencapsulated Spirulina biomass could be added to biscuits without sensorial loss. Upon spray-drying microencapsulation with octenyl succinic anhydride modified starch, addition of 20% of Spirulina biomass did not change biscuits sensory acceptance and purchase intent scores, with the exception of a 7% decrease in the appearance, probably because off-flavors were masked. The acceptance index for these biscuits was 79.2%, suggesting market potential. This technological approach led to the production of biscuits with 40% more proteins and that could have a claim as a nutritional source of iron (one portion equals to 16% and 35% of the RDA for premenopausal women and men, respectively). Considering its wide use and low cost, spray-drying encapsulation emerges as a successful strategy to employ microalgae for nutritional enrichment by the food industry.
查看更多>>摘要：In wine, polyphenols are closely associated with astringency, bitterness, color and aroma. Some of these sensory parameters have been reported to be dynamically perceived during wine tasting. In this study, time-dependent sensory methodologies (Temporal Dominance of Sensations or TDS, and Temporal-Check-All-That-Apply or TCATA) were used to characterize wines made from six grape varieties. Sensory analysis was contrasted against the phenolic composition of wines. Temporal sensory methods revealed differences among wines which did not reflect the limited differences observed between wine phenolics. However, some significant associations could be described, namely, detection time of bitterness with concentration of proanthocyanidin polymers, colorimetric variables with content of anthocyanins, and dominance and higher incidence of bitter taste with contents of tyrosol and flavonols. Astringency showed no relationship with any single polyphenol or specific group of polyphenols. It is concluded that, despite the major contribution of polyphenols to wine composition, their unique and independent influence on time associated sensory aspects should be critically scrutinized due to the multifactoriality of elements participating in the perception of a temporary sensation.
Lemos, Wilson J. F., Jr.Binati, Renato L.Bersani, NicoloTorriani, Sandra...
8页
查看更多>>摘要：Glutathione (GSH) is the most abundant non-protein thiol in yeasts and plays an important role as antioxidant in wine. Application of selected GSH-accumulating strains can improve wine sensorial quality and stability, but most selection programs have been conducted on Saccharomyces cerevisiae. Therefore, the aim of the study was to evaluate the ability of different non-Saccharomyces yeasts, i.e. Lachancea thermotolerans, Metschnikowia spp. and Starmerella bacillaris, to produce glutathione. This feature was evaluated in an optimized medium under aerobiosis (MGSH) and in microfermentations using synthetic grape juice (SGJ) and pasteurized grape juice (PGJ), in single or sequential inoculations with S. cerevisiae. The non-Saccharomyces yeasts showed a good capacity to produce GSH, particularly Metschnikowia spp., which achieved significantly greater concentrations. As expected, the strains presented higher growth and glutathione accumulation in MGSH than in SGJ and PGJ. In the microvinification trials, GSH production was higher in PGJ than SGJ, while cell growth was similar, indicating the influence of grape juice composition on GSH metabolism. Taken together, our results demonstrated that selected non-conventional yeast strains, with proven interesting oenological traits, have a good potential to produce GSH, and thus are more suitable and worthwhile for application as active or inactivated dry yeasts preparations.
查看更多>>摘要：Cod liver oil (CLO) has many health and dietary benefits, but is prone to rapid deterioration and developing undesirable odor. The aim of the research was to evaluate a functional beef burger fortified with CLO mono-layered (ME) and bilayered (BE). CLO microcapsules were characterized for morphology (scanning electron microscopy), particle size distribution (light refractometer), thermal stability (differential scanning calorimeter), and encapsulation efficiency (in vitro release). Oxidative stability of the fortified burgers including pH, TBARS, and peroxide value (PV) during storage (4 +/- 1 degrees C up to 15 days) was evaluated. The CLO microcapsules have highly uniform, droplet size was 874 nm, and accumulative release was 79.35% in 270 min in stimulated gastrointestinal. Also, found that CLO microcapsules were stable at different pH, cooking temperature, and storage at 4 +/- 1 degrees C up to 15 days. Significant decrease in pH, TBARS, and PV in a fortified burger with microcapsules compared with unencapsulated and/or control samples. CLO-microcapsules enhanced sensory attributes of beef burger during storage and even after cooking, while burger with CLO-direct addition was rejected. Results demonstrated that CLO microcapsules as vehicles were stable at cooking temperature, keeping oil from oxidation, and improving the sensory attributes of burgers.
查看更多>>摘要：Zhuhoujiang is a popular fermented soybean paste in China. The aroma profiles of Zhuhoujiang were systemically analyzed by gas chromatography-olfactometry/mass spectrometry (GC-O/MS). A total of 100 aroma compounds were detected, and 24 compounds were identified as the important aroma compounds by odor intensities and odor-activity values (OAV) analysis. Ethyl isovalerate, ethyl isobutyrate, linolenic acid, and eucalyptol were demonstrated to be the key aroma compounds of Zhuhoujiang by omission tests. Ethyl acetate, myrcene, and eucalyptol were strongly correlated to the cooling aroma characteristic of Zhuhoujiang, whereas ethyl isovalerate, ethyl isobutyrate, ethyl 4-methylvalerate, ethyl 2-methylbutyrate, linolenic acid, and D-limonene contributed most to the sweetness and aromatic flavor. Furthermore, full two-dimensional gas chromatography-mass spectrometry (GC x GC-TQMS) was applied and another 118 aroma compounds were identified including 48 esters.
查看更多>>摘要：On a lab-scale, glycation is generally a lengthy process that would be costly if replicated on an industrial scale. In this study, a simplified method for glycating soy protein isolate has been developed. Soy proteins were glycated with allulose, fructose, and glucose in the presence of water. Free amino group content, protein solubility, browning index, and reducing sugar concentration were measured for the glycated proteins. Fourier Transform Infrared (FT-IR) spectroscopy was used to examine structural changes, and hydration behavior was evaluated using Time Domain Nuclear Magnetic Resonance (TD-NMR) relaxometry through T-2 relaxation time measurements. The results showed that proteins could be glycated under these austere conditions and with minimal control. It was found that high temperatures were not favorable for glycation, and lower temperatures could be preferred. At high temperatures, proteins become more denatured and less soluble, as shown through the Lowry method for protein solubility and TD-NMR results. Higher browning was observed at a higher temperature, primarily when allulose and fructose were used for glycation. The highest glycation was obtained with glucose, while allulose and fructose showed the lowest reactivity under the proposed conditions. Proteins with low solubility had longer T-2 relaxation times, indicating more free water and weaker water-binding capability.
查看更多>>摘要：Mechanochemical-assisted extraction (MCAE) was first applied to extract total protein from watermelon seeds with grinding medium of surfactant instead of alkaline. The optimal conditions of MCAE, that is, sodium bis(2-ethylhexyl)sulfosuccinate (AOT) concentration of 0.10 mol/L, water content of 20, ionic strength of 0.05 mol/L, aqueous phase pH of 7, solid to liquid ratio of 0.2 g/mL, ball milling speed of 523 rpm and ball milling time of 10.5 min were obtained by response surface methodology. The highest yield (489.967 +/- 1.214 mg/g) of watermelon seeds protein (WSP) was obtained under the optimal conditions, which corresponds to an increase of 19.7% in comparison with that extracted by conventional alkaline extraction. When considering the secondary structure of protein by FTIR and SEM analysis, the random coil structure of watermelon seeds protein was obviously increased and protein aggregations were apparent by conventional alkaline extraction, suggesting the denaturation of WSP under relatively alkaline environment and no loss of protein activities with surfactant interactions, thus MCAE with surfactant retained the better quality of WSP. The results indicated that MCAE with surfactant could be a protective and effective method for the extraction of natural oil-seeds protein.
查看更多>>摘要：This study investigated effects of the high molecular-weight (800 kDa) chitosan coating on quality and shelf life of channel catfish (Ictalurus punctatus) fillets stored at 4 degrees C. Distilled water (control), CHAC1% (1% w/v chitosan in 1% v/v acetic acid), AS3% (3% w/v aspartic acid), and CHAS3% (3% w/v chitosan in 3% w/v aspartic acid) were used as coating solutions. Microbial (total aerobic mesophilic bacteria-TAMB; total aerobic psychrophilic bacteria-TAPB), physicochemical, and consumer perception parameters of chitosan-coated catfish fillets were analyzed at 0, 3, 6, 8, and 10 days. Chitosan coating treatments, especially CHAS3%, effectively inhibited microbial growth, delayed lipid oxidation, reduced cooking loss, and retained water holding capacity, color, and texture. Overall acceptance and purchase intent of CHAS3% fillets drastically decreased from 6.16 to 84% on the 8th day to 4.31 and 44.67% on the 10th day of storage. Shelf life of catfish fillets was extended by CHAS3% from 6 days to 8 (based on consumer acceptance) and/or 10 (based on TAMB and TAPB) days compared to the control. This study demonstrated that CHAS3% coating showed promise as a natural preservative to extend shelf life by delaying chemical and microbial deterioration of refrigerated catfish fillets, and potentially for other fish fillets.
NSTL
Elsevier