查看更多>>摘要：The effect of frozen storage periods (0, 2, 4, 6, or 8 wk) of raw chicken meat on its flavor upon stewing was investigated by analyzing the changes of free amino acids (FAAs), 5'-nucleotides, minerals and volatile compounds and by evaluating the taste and aroma profiles using an E-nose and a human panel. Results showed that the storage time of raw material improved its taste and aroma profiles upon stewing. The total free amino acid contents and the equivalent umami concentration (EUC) increased from 159.90 mg/100 g and 3156.58 mg/100 g to 292.81 mg/100 g and 4360.72 mg/100 g, respectively, although the 5'-nucleotide concentrations decreased upon stewing. With increased frozen storage durations of raw material, the contents of the mineral elements and total volatile compound increased firstly, then deceased. Results from the electronic nose and sensory evaluation indicated a progressive difference in the overall flavor profiles among samples. The meaty, umami and salty traits of stewed meat reached the maximum scores as frozen chicken meat was stored for 6 wk, which should be related to the enhanced migration of taste-active substances and retention of aldehydes. Overall, a limited frozen storage duration of raw meat can enhance its flavor upon stewing.
Sadeghi, RohollahLin, YulianPrice, William J.Thornton, Michael K....
6页
查看更多>>摘要：The texture quality of French fries is critical to the potato processing industry. Sensory evaluation via testing mouth sensation or by visual and finger spinning inspection are the primary methods to assess French fry texture quality. Instrumental texture analysis has not been practically used due to data inconsistency. This study aimed to minimize variations of instrumental analysis and identify instrumental parameters with strong correlations to a sensory evaluation to enhance the effectiveness of the texture quality assessment. This research was carried out on an industrial scale and utilized 10 potato varieties to increase the texture variation of samples. The sensory evaluation by the visual and finger spinning inspection was performed following industrial procedures and standards. Results showed instrumental crispness and crunchiness, as represented by the slope of the first significant fracture and the number of fractures of the force-distance curve in a cut test with a T-42 blade, were strongly correlated with desirable sensory attributes. Microstructure examination revealed that a low level of crust compactness was associated with instrumental crispness and crunchiness. The procedure advanced in this study had a small data variation and concluded that instrumental crispness and crunchiness are strong indicators of premium French fry texture quality.
查看更多>>摘要：Concerns related to foodborne pathogens such as Salmonella enterica serovar Enteritidis (SE) necessitate the decontamination of eggs. Multiple studies have successfully demonstrated the use of non-thermal plasma (NTP) technology in inactivating SE on artificially inoculated shell eggs. However, the NTP devices abovementioned were operated in the batch mode and small scale. The present study is the first attempt to evaluate the effectiveness of a large-scale device using NTP for egg decontamination. The designed NTP was operated at 400 W (power), 30 slm (Ar flow rate), 5 and 10 eggs/min (speed of conveyor belt), and 4 cm (distance between the plasma jets and egg samples). Conducting a two-round treatment for the egg samples at 400 W-30 slm-5 eggs/min-4 cm achieved the highest reduction of SE populations (3.57 log CFU/egg). SEM observation revealed less damage on the surface of the plasma-treated eggs than the commercial-washed eggs. Overall, NTP treatment can maintain the freshness quality and sensory characteristics until 15-day storage. This study demonstrated a large-scale NTP system was able to effectively achieve a significant reduction of pathogenic SE without adversely affecting egg quality properties. These results suggested the readiness of this NTP device for industrial applications.
do Prado-Silva, LeonardoAlvarenga, Veronica O.Braga, Gilberto U. L.Sant'Ana, Anderson S....
7页
查看更多>>摘要：Antimicrobial photodynamic treatment (aPDT) is a promising alternative to conventional thermal inactivation methods. This study aimed to evaluate Bacillus cereus vegetative cells' inactivation and spores by aPDT with new methylene blue (NMB) as photosensitizer (PS) using red light. The efficacy of aPDT was determined initially by minimal inhibitory concentration (MIC) of NMB at different concentrations and fluences. Cluster analysis from the results of MIC grouped B. cereus strains according to their aPDT susceptibility. Then, four strains (B63, B3, 436, and ATCC 14579) were selected for a survival study of aPDT with NMB in three concentrations (5, 50, and 100 mu M). The viability of B. cereus vegetative cells and spores was reduced in all tested fluences. The strain ATCC 14579 (vegetative cells and spores) was the most susceptible to aPDT at relatively low fluence (25 J/cm(2)). The Weibull model presented a good fit for the inactivation data estimating the kinetic parameters delta (first decimal reduction) and p (shape parameter). This study contributes to the knowledge of the behavior of different strains of B. cereus regarding an emerging method of microbial inactivation. The variability of inactivation among strains will allow the development of more reliable processes.
查看更多>>摘要：The study aims at assessing the gluten aggregation properties of wholemeal semolina for the differentiation of durum wheat cultivars with different amounts of gluten-quality related fractions. To this end, a calibration set of 56 durum wheat cultivars harvested in 2015-2016 was categorized into four quality classes based on the total gluten protein content and the glutenin to gliadin ratio. Quality class distribution was carried out by Principal Component Analysis (PCA) performed on either gluten aggregation parameters alone or with gluten fractions. PCA differentiated high and medium-high quality varieties from those of low and medium-low quality. Furthermore, PCA confirmed the relationship between gluten fractions and their aggregation kinetics, by means of a validation step consisting of 22 cultivars harvested in 2016-2017. In conclusion, gluten aggregation properties proved to be good indicators of durum wheat semolina quality, and thus a reliable tool for blend preparation in the pasta-making process.
查看更多>>摘要：Human milk is a natural source of medium-chain fatty acids (MCFAs). It is generally acknowledged that MCFAs exist in medium-chain triacylglycerols (MCTs). However, a previous study revealed that human milk is naturally rich in medium- and long-chain triacylglycerols (MLCTs). Few data are available on the MLCT composition of preterm milk. This study compared the MCFA and MLCT profiles in human milk from mothers after preterm (28-37 weeks) and term (>37 weeks) delivery during three lactational stages. The results showed that almost half of the triacylglycerol species in human milk are MLCT, accounting for approximately 30% of the total TAGs, mainly composed of one MCFA and two long-chain fatty acids, that is, MLL-type MLCT. In addition, MCFAs and MLCTs showed an increase from colostrum to transitional milk, while they were comparable between preterm and full-term milk. This research could help to develop infant formula, which is of great significance for infants.
查看更多>>摘要：Crispness is an important textural attribute of puffed snacks. Impregnation pretreatment is used to regulate the texture of puffed products by changing the cell structure and mechanical properties. In this study, the influence of citric acid and sucrose pretreatment on the cell structure, cell wall components, and mechanical properties of peach slices before puffing drying (heat-pressed slices) was evaluated to understand how citric acid and sucrose pretreatment affects the pore structures and texture characteristics of peach chips with improved crispness. Cell wall degradation, cell structure morphology and mechanical properties before puffing drying interacts to govern the pore morphology and texture characteristics of peach chips. Micrographs of heat-pressed slices showed swollen structures for Cit (citric acid) treated samples and compacted structures for Cit + Suc (citric acid and sucrose) and Cit + Suc + Sdp (citric acid, sucrose and sodium dihydrogen phosphate) treated samples. An increased elastic modulus and decreased viscosity index were observed in all Cit-, Cit + Suc- and Cit + Suc + Sdp-treated samples. After puffing drying, Cit prompted the generation of large pores with low hardness, and Suc and Sdp enhanced the emergence of uniform and small pores with increased hardness. Therefore, crispness was attained by regulating crumbly texture through Cit and regulating hard texture through Suc and Sdp.
查看更多>>摘要：The effects of the inoculation with autochthonous lactic acid bacteria (LAB) strains (Lactobacillus sakei BL6, Pediococcus acidilactici BP2, and Lactobacillus fermentum BL11) on the pH, lipid oxidation, protein oxidation, volatile compounds, and sensory evaluation of beef jerky were investigated. The pH, thiobarbituric acid reactive substances, and carbonyl contents of the inoculated jerky were significantly lower than those of the control (P < 0.05). A total of 61 volatile compounds were identified and quantified. L. sakei BL6 inoculation led to higher carbohydrate fermentation-derived volatile compound contents, whereas P. acidilactici BP2 inoculation led to higher contents of volatile compounds derived from lipid beta-oxidation, amino acid metabolism, and esterase activity. According to the sensory analysis, the jerky inoculated with P. acidilactici BP2 had the highest acceptability score. In conclusion, inoculation with P. acidilactici BP2 enhanced the flavor profile and acceptability of beef jerky.
查看更多>>摘要：The present research aimed to study the effect of Ohmic heating (OH) treatment on textural degradation and as a pretreatment step prior to drying freshly cut pineapple (Anana comosus) cubes. The fresh samples were heated up to 90 degrees C with electric field strength (EFS: 25, 30, 35 V/cm) for a time duration (60, 90, 120, 150, 180 s), and the textural degradation and color changes were studied. The OH treated samples were dried in a tray drier at 70 degrees C with an airflow of 0.1 m(3)/s and the rehydration of these dehydrated samples was carried out at room temperature (25 +/- 1 degrees C) for 7 h in distilled water. It was found that the maximum textural degradation occurred with the treatment time 90 and 120 s for the respective EFS. The effective moisture diffusivity during drying of the OH treated samples was found to be in the range of 1.91 x 10(-8) to 2.30 x 10(-8) m(2)/s. Non-significant differences of % mass gain and rehydration ratio were observed to increase treatment time at p > 0.05. Based on the current study, OH heating can be used as an alternative to conventional blanching of fruits and vegetables prior to drying and storing.
Bambace, Maria F.Alvarez, Maria, VMoreira, Maria R.
8页
查看更多>>摘要：The prevalence of lactose intolerance, milk protein allergies, and the increasing vegan population have led to a growing demand for probiotic products based on non-conventional food matrices. In this study, the potential use of fresh blueberries as carriers of Lacticaseibacillus casei CECT 9104 and Bifidobacterium animalis subsp. lactis CECT 8145 incorporated into alginate-based prebiotic coatings was evaluated. Protective effect of inulin + oligofructose on probiotic viability, microbiological and sensory quality of fruits, and also, antagonistic effects of probiotics on co-inoculated E. coli O157:H7 and L. innocua were the main parameters studied along 14 days of refrigerated storage. A protective effect was observed since prebiotic enrichment allowed maintaining both L. casei and B. lactis viability above the minimum recommended levels (10(6) CFU/g) up to the end of storage, and therefore, ensuring their beneficial health action. Regarding safety issues, both probiotics exerted a biocontrol effect on inoculated L. innocua with reductions up to 2.31 log. Moreover, enrichment of blueberries with B. lactis through the application of prebiotic coatings maintained quality and sensory characteristics for 14 days at 5 degrees C. Thus, the development of functional blueberries coated with prebiotic-probiotic mixtures was achieved. These ready-to-eat fruits constitute novel, healthy and multifunctional alternatives of non-dairy probiotic foods that would allow meeting the current consumer demand.
NSTL
Elsevier