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关键词： Electric field strength   Ohmic heating   Total dietary fiber   In silico analysis   Polyphenol oxidase  

摘要： Ohmic heating (OH) is an emerging technology with potential for pasteurization and enzyme inactivation in mango pulp. This research aimed to investigate the effect of OH and conventional boiling treatment (CT) at moderate pasteurization conditions (72 degrees C, 2 min) on the physicochemical characteristics and the polyphenol oxidase (PPO) residual activity in Ataulfo mango pulp. Pulp's physical features, such as titratable acidity (TA) and pH did not show differences (p > 0.05) between treatments, whereas OH increased the apparent viscosity of mango pulp (10.26-15.64%). This effect was associated to a higher release of insoluble fiber. Both thermal treatments affected the color (Delta E values > 5) of mango pulp. PPO inactivation reached 95.7 +/- 5.9% after 15 s with both thermal treatments. In silico molecular dynamics suggested that temperature and pH contributed to the PPO inactivation by inducing modifications in its catalytic site and altering the protein-substrate interaction. Our results indicate that OH is an effective technology to inactivate PPO at moderate pasteurization conditions (72 degrees C, 15 s), with minimal modifications on the physicochemical properties of Ataulfo mango pulp.

关键词： Fruits  

摘要： The present investigation was carried with the objective of developing kiwi fruit leather using different hydrocolloids. Hydrocolloids like xanthan gum (XG), guar gum (GG), and pectin (P) in three different concentrations, that is, 0.2%, 0.5%, and 1% were blended with kiwi pulp and were dried at 60 degrees C for around 7 hr. The developed kiwi fruit leathers were analyzed for physicochemical, color, textural and organoleptic properties. The leather samples prepared with 0.5% XG, 0.5% GG, and 0.5% P showed the highest sensory score and desirable physicochemical properties. The effects of air temperature (50, 60, 70 degrees C) and hydrocolloids (0.5% of XG, GG, and P) on the drying kinetics of kiwi fruit leather were investigated. The mathematical modeling was performed by seven thin layer drying models. The Midilli-Kucuk model was found to satisfactorily describe the thin layer drying kinetics of kiwi fruit leather. Practical applications Kiwifruit is a rich source of vitamins, minerals, antioxidants, phytochemicals, and fiber content. It offers specific health benefits and has great potential for industrial exploitation. However, this fruit and its products are not reachable to all consumers. Fruit leathers are an economical and convenient substitute for natural fruits with high nutritional values. But leather making from kiwifruit and leather drying is a challenging task. Hence, it was hypothesized that xanthan gum, guar gum, and pectin could be effective for providing desirable textural, and organoleptic properties. Thus, the objectives of this study were to evaluate the effects of xanthan gum, guar gum, and pectin and their concentrations on the characteristics of kiwi fruit leather and to investigate the effect of drying air temperature on the drying kinetics of kiwi fruit leather. This study will provide an opportunity to food industries for the effective utilization of kiwifruit.

关键词： Water quality monitoring   Spatiotemporal   Limnological   Univariate and Multivariate   Corumbá   IV reservoir   Brazil  

摘要： The study presents the characterization of the water quality of the Corumba IV reservoir in the State of Goias, in the Brazilian Cerrado biome, based on data from the operation period between 2007 and 2017. Few are known about the temporal and spatial variations in the water quality of the reservoir. Up to now, the water quality has been analyzed only from the point of view of compliance with the limits required by Brazilian environmental legislation. Therefore, the integrated analysis of water quality parameters and water body dynamics may bring important information to support decision-making in reservoir management. An exploratory analysis of the limnological data series provided by the company in charge of the hydroelectric plant was then carried out. Univariate and multivariate statistical techniques were applied to analyze the data period from 2007 to 2017. The results identify four distinct limnological phases representing the transition of the environment. The first phase (2007 to 2009) characterized by the decomposition of the flooded vegetal organic matter and subsequent phases, after 8 years (2010 to 2017), have featured the transition process from the lotic condition to the consolidation of the lentic environment. The spatial analysis of the results demonstrates that tributaries influence the water quality of the reservoir differently, probably due to the different impacts suffered in the sub-basins (e.g., sewage discharges;runoff). Although it is possible to evidence the impact of anthropic activities on water quality, the reservoir still presents characteristics of an environment with low trophic status.

关键词： fuzzy clustering   nutrients   chlorophyll   association rules  

摘要： Machine Learning (ML) is an increasingly accessible discipline in computer science that develops dynamic algorithms capable of data-driven decisions and whose use in ecology is growing. Fuzzy sets are suitable descriptors of ecological communities as compared to other standard algorithms and allow the description of decisions that include elements of uncertainty and vagueness. However, fuzzy sets are scarcely applied in ecology. In this work, an unsupervised machine learning algorithm, fuzzy c-means and association rules mining were applied to assess the factors influencing the assemblage composition and distribution patterns of 12 zooplankton taxa in 24 shallow ponds in northern Italy. The fuzzy c-means algorithm was implemented to classify the ponds in terms of taxa they support, and to identify the influence of chemical and physical environmental features on the assemblage patterns. Data retrieved during 2014 and 2015 were compared, taking into account that 2014 late spring and summer air temperatures were much lower than historical records, whereas 2015 mean monthly air temperatures were much warmer than historical averages. In both years, fuzzy c-means show a strong clustering of ponds in two groups, contrasting sites characterized by different physico-chemical and biological features. Climatic anomalies, affecting the temperature regime, together with the main water supply to shallow ponds (e.g., surface runoff vs. groundwater) represent disturbance factors producing large interannual differences in the chemistry, biology and short-term dynamic of small aquatic ecosystems. Unsupervised machine learning algorithms and fuzzy sets may help in catching such apparently erratic differences.

关键词： Emotional response   Oenological parameters   Volatile profile   Young consumers   Red wines  

摘要： To gain deeper understanding on young consumers' attitudes and preferences to wines is needed to connect wine industry with the youth. The aims of the present study were (i) to define 'trendy wine' for young consumers and (ii) to identify chemical drivers of liking in red wines for the youth. The study was divided in two phases: phase I explored young consumers' attitudes towards wines using an online survey, and phase II studied the relationship between hedonic and emotional responses elicited by 12 red wine samples and their physico-chemical characteristics. Consumers' responses and physico-chemical data were related using Principal Component Analysis (PCA). Results of the online survey showed that trendy wines were associated to: sparkling, soft, fresh, fruity, sweet, light, and balanced wines. Also, young consumers reported that, although flavor was considered the most important attribute, price and Protected Designation of Origin could be valuable attributes. PCA results of phase II showed that wines with a lower ratio [total polyphenol index/polysaccharides] were more liked and elicited more positive emotions than wines with higher total polyphenol index, color intensity, volatile acidity, and alcohol content. Liking and positive emotions were positively related to higher Odor Activity Values of the volatile compounds from the organic acids group. The presence of benzenoids and lactones, and the lower presence of terpenoids & norisoprenoids were associated with negative emotions. In conclusion, red wines should be soft (described as lower ratio [total polyphenol index/polysaccharides]), and have floral, and fruity aromas to better connect with young consumers.

关键词： complex aquifer   karst   hydrogeology   groundwater pollution risk map   integrative approach   water resources management   Syria  

摘要： Groundwater is the main resource for irrigation and drinking supply in most parts of Syria, as for most Mediterranean countries, however this resource suffers from mismanagement. In the study area (northeast of Mt. Hermon), the lack of information makes water management in this area extremely difficult. Assessing groundwater pollution risk is the most essential issue for water resources management, especially in the regions where complex interaction between climate, geology, geomorphology, hydrogeology, water scarcity and water resource mismanagement exist. This complexity leads to significant complication in determining pollution risk of studied system. In the present work, we adopted an integrative approach to assess groundwater pollution risk in the study area. This methodology is based on the analysis of hydrogeological characteristics of aquifer systems and the available information about socioeconomic context and physiochemical groundwater conditions that might affect this system. This approach allowed us to delineate the groundwater pollution risk map based on the analysis of concerning parameters/indicators. The degree of risk was assessed as the sum and average of rating of these parameters and indicators for each subarea. Typically, very high pollution risk index was identified over the Quaternary/Neogene horizon, i.e., shallow and unconfined aquifer and in the lower part of Jurassic aquifer. In these two parts, the majority of anthropogenic activities are concentrated. Low pollution risk index was found for the outcropping of low permeable Quaternary basalt at the Southern part of the study area. A moderate pollution index was identified for the low/moderate permeability of silt, clay and marly limestone-rich horizons of the major part of Neogene aquifer outside of the intersected zones with Quaternary aquifer and for the Paleogene formations. The spatial analysis shows that about 50% of the study area is characterized as being at very high and high pollu

关键词： Textures  

摘要： Pasta is a popular food throughout the world and its quality can be measured mainly by its appearance, taste, and texture. The aim of this work was first to produce fresh multigrain pasta with a maximization of the sensorial properties and then evaluate the effects of the unconventional flours (rice, oat, and soy) on the physicochemical properties and sensory profile. Soy flour alone contributed to most modifications, such as an increase in yellow color (8.9-13.5, b* parameter), a decrease in the homogeneous appearance, texture (4.4-1.7 N), and cooking time (13 to 8.3 min). However, the mixture of the three flours contributed to increasing the sensorial hardness (2.1-4.1), making it more al dente as expected for fresh pasta. Fresh pasta with a mixture of rice, oat, and soy flour improves the nutritional value of the pasta in relation to control, increasing the protein (17.8 to 32.6 g/100 g) and ash (2.5 to 2.9 g/100 g) contents, and reducing the content of carbohydrates (77.6 to 62.4 g/100 g). In addition, the lipid (1.95 and 2.0 g/100 g), and caloric values (399.6 and 398.3 kcal) remained the same for fresh control and enriched pasta, respectively. Novelty impact statement The incorporation of unconventional flours can be used as a vehicle to provide important nutritional components;Soy flour contributed with the yellow color of fresh multigrain pasta;Fresh multigrain pasta can be more al dente as expected for fresh pasta.

关键词： Dried apple chips   Gamma irradiation   Storage quality   Nutritional enhancement   Color score   Overall acceptability  

摘要： In the present study dried apple chips packed in polyethylene packs were gamma irradiated in the dose range of 1.0?3.0 kGy. Irradiated samples including control were stored under ambient (10?2?15 ? 2 ?C, RH 60?70%) conditions and evaluated at intervals of 2 months for physico-chemical, sensory and microbial quality parameters. Results revealed that dose levels of 2.5 kGy and 3.0 kGy proved significantly (p < 0.05) beneficial in enhancing the nutritional quality besides maintaining color and texture attributes during storage. Post-drying irradiation treatment at 3.0 kGy increased the total phenol content by 6.6%, total and reducing sugars by 4.2% and 18.8% respectively. Results of the antioxidant activity revealed a significant (p < 0.05) decrease in EC50 values of apple chips following post drying irradiation. EC50 values of apple chips irradiated at 2.5 kGy and 3.0 kGy were significantly (p < 0.05) lower than standard antioxidants for hydroxyl radical scavenging activity. Data pertaining to Hunter color score indicated that during storage, percentage increase in browning was 40.4% in control compared to 21.9% in 3.0 kGy irradiated samples. The above irradiation treatments maintained significantly (p < 0.05) higher overall acceptability of apple chips and resulted in about 2.5 log reduction in microbial load just after irradiation and 2.1 log reductions after 6 months of storage under ambient conditions.

关键词： chicken breast   myofibrillar protein   physicochemical property   protein structure   ultrasound‐   assisted immersion thawing  

摘要： This study evaluated the effect of air thawing (AT), water thawing (WT), and ultrasound-assisted immersion thawing (UT) at different power levels (200, 300, 400, and 500 W) on the thawing rate, physicochemical properties, and protein structure of chicken breast muscle (pectoralis), and the weight of each sample was approximately 106 +/- 3 g. UT shortened the total thawing time and decreased the cutting force with increasing ultrasound power. Additionally, UT at 300 W (UT-300) remarkably reduced the thawing and cooking losses of the samples compared to AT, WT, and other UT powers (p < 0.05). Low-field nuclear magnetic resonance spectroscopy showed that the T-21 and T-22 of the UT-300 samples were shorter than those of the AT and WT samples (p < 0.05), which revealed that UT-300 reduced the mobility and losses of both immobilized and free water. Moreover, UT-300 remarkably reduced the damage to the myofibrillar protein (MP) structure. Overall, with appropriate ultrasonic power, the thawing rate increased and changes in the MP structure were reduced. Practical Application This study found that compared to that of AT samples, the thawing time of the UT-300 samples markedly decreased by 57%. In addition, UT-300 could reduce the damage to the myofibrillar protein structure, which was very beneficial for further processing of frozen foods.

关键词： Starch  

摘要： Nixtamalization process conditions such as grinding and drying increases stiffness in the starch;consequently, swollen capacity, water binding capacity, and water solubility index decrease. These affect cohesion characteristics, flow behavior, and textural parameters of flour, masa, and tortilla. The aim of this study was to evaluate the changes in physicochemical, morphologic, and vibrational properties of flours and masa considering the variation of drying and milling conditions. Water absorption index and water solubility index changes are attributed to nixtamal wet grinding. Scanning electronic microscopy analysis showed starch granules with greater gelatinization. Pasting profile analysis and changes observed in IR spectra indicate that drying and grinding methods are influential in the quality of flours. The study of masa rheological parameters indicated that drying influenced masa viscoelasticity. These results showed that drying temperature and wet grinding of nixtamal are necessary conditions to obtain flour and masa and determine the quality of its products. Practical applications Mills discs distance and nixtamal drying temperature are process conditions that influence physical, chemical, and structural changes of the starch, which modify the rheological behavior of flours and masa. Likewise, tortilla is a food of greater consumption among the Mexican population, and its textural quality depends on flour and masa quality.