10,392 research outputs found

    Substantiation Of Hot Smoking Parameters Based On Sensory Researches In Hot Fish Marinades Technology In The Jelly Pouring

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    Modern technologies of food products provide creation of healthy, tasty and safe products, characterized by high organoleptic properties, balance by main food factors and structural-mechanical parameters of a product.The main technological process in the technology of fish marinades and a jelly pouring is the hot smoking. Technological parameters of the hot smoking have been scientifically grounded on the base of the statistical processing of data of sensory studies. Organoleptic assessment of semi-products after the thermal processing was carried out by 5-point system corresponding to the elaborated scale. The quantitative assessment of organoleptic parameters of the quality of experimental samples was determined by the totality of all assessment points, taking into account chosen weight coefficients depending on the importance degree of a given parameter at forming consumer qualities of a product. The generalizing quality parameter was calculated as a sum of assessments of organoleptic parameters – taste, consistence and appearance. Individual assessments of separated quality parameters of products (in points) were put in degustation lists and statistically processed by the averaging method.The smoking process realization, according to scientifically grounded parameters allows to produce the new type of tasty, healthy and presentable culinary products of a perspective object of Ukrainian aquaculture – silver carp of a prolonged storage term

    Analytical methods in wineries: is it time to change?

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    A review of the methods for the most common parameters determined in wine—namely, ethanol, sulfur dioxide, reducing sugars, polyphenols, organic acids, total and volatile acidity, iron, soluble solids, pH, and color—reported in the last 10 years is presented here. The definition of the given parameter, official and usual methods in wineries appear at the beginning of each section, followed by the methods reported in the last decade divided into discontinuous and continuous methods, the latter also are grouped in nonchromatographic and chromatographic methods because of the typical characteristics of each subgroup. A critical comparison between continuous and discontinuous methods for the given parameter ends each section. Tables summarizing the features of the methods and a conclusions section may help users to select the most appropriate method and also to know the state-of-the-art of analytical methods in this area

    On-line monitoring of the transesterification reaction carried out in microreactors using near infrared spectroscopy

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    Biodiesel can be produced from vegetable oils, animal fats, and waste cooking oils by transesterification with ethanol (also called ethanolysis) in order to substitute fossil fuels. In this work, the batch ethanolysis of high oleic sunflower oil was transferred into a continuous microstructured device, which induces a better control of heat and mass transfers. Various parameters were studied, notably the initial ethanol to oil molar ratio. An innovative method using NIR spectroscopy was also developed to on-line monitor the transesterification reaction of high oleic sunflower oil with ethanol in microreactors (circular PFA tube 1/1600 OD, 0.0200 ID). The reactions were monitored directly in the microreactors through sequential scans of the reaction medium by the means of an adequate probe. The asset of the method is that no sample collection or preparation is necessary. Partial Least Squares regression was used to develop calibration and prediction models between NIR spectral data and analytical data obtained by a reference method (gas chromatography with flame ionization detection, GC–FID). This method is fast, safe, reliable, nondestructive and inexpensive contrary to conventional procedures, such as gas chromatography and high performance liquid chromatography generally used to determine the composition of crude transesterification medium

    Modelling crystal growth from pure and impure solutions : a case study on sucrose

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    Tese de doutoramento. Engenharia Química. 2006. Faculdade de Engenharia. Universidade do Port

    Безопасность и качество пищевых продуктов = Practical Food Safety and Food Quality : практикум

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    Даны описания практических и лабораторных работ, проводимых в рамках курсов «Международные стандарты и безопасность продуктов питания» и «Контроль качества биотехнологических продуктов». Задания сопровождаются подробными комментариями. Используются активные формы обучения, такие как работа в команде, игровые технологии и пр. Для иностранных и российских студентов, обучающихся на английском языке, изучающих пищевую биотехнологию, контроль качества и безопасность пищевых продуктов

    Assessment of target purity difference for a Louisiana sugar mill

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    The main goals of a “raw” sugarcane factory are to have an efficient profitable operation with the required sugar quality and maximum sugar recovery. The loss of sugar to final molasses accounts for 45 to 47% of the total sugar losses. An estimation of the average cost of the manufacturing losses for the 2007 harvest season was approximately $9 million – the sugar lost to the final molasses accounts for approximately 50% of this cost (Salassi, 2008). For final molasses, the “Target Purity” (or equilibrium purity) refers to the minimum level of sucrose that theoretically remains in solution for a fixed composition of non-sucrose substances. The “Target Purity Difference” (TPD), which is the difference between the actual “True Purity” and the “Target Purity,” is the non-bias measurement of factory performance. TPD was used for this research to define the operational goals of the low-grade station, toward reaching the physical maximum molasses exhaustion. The approach to molasses exhaustion for the studied factory was focused on the low-grade station stages of the boiling house which include: 1) continuous cooling crystallizer’s performance; 2) molasses consistency; 3) supersaturation; 4) crystal size distribution and crystal content; and 5) purity drop and goals by stage. The main recommendations are: 1) to increase the crystal content in the “C” massecuite at the exit of the continuous vacuum pan (CVP) by regulating the seed/massecuite ratio and Brix profile; and 2) to improve the flow pattern and cooling temperature control in the vertical crystallizers by modifying the internal arrangement (baffles and cooling coils arrangement) and placing more temperature probes. Complementary recommendations are: 1) implement procedures for seed preparation (slurry preparation by ball milling); 2) increase grain strike capacity according to the expected “C” massecuite rate; 3) grain batch pan automation; and 3) monitor and control crystal size distribution per stage according to standard desired values. The establishment of a routine to measure purity drop/rise and crystal size distribution specifying achievable goals per stage at the low-grade station is the best tool to achieve the ultimate goal (zero target purity difference)

    Product Parameters Optimization for Double Purge of C-Magma Integrated with Conventional Three-Boiling Crystallization Scheme to Improve Raw Sugar Whole Color

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    Efficient crystallization in raw sugar production is the result of a combination of factors and responses that meet specific criteria. Matching a sugar quality standard, maximizing sugar yield, maximizing crystallization equipment capacity and minimizing heat requirement are all necessary optimization criteria. A double centrifugation or purge of C-magma is intended to improve raw sugar whole color by the reduction of color recirculation with the sugar crystal. Combining a three boiling crystallization scheme with a second centrifugation after the last crystallization stage required optimizing the input/output product parameters (purities) and the location of the liquid recycle component (double purge molasses) for efficient integration. Sugars™ and JMP® were software programs used to solve this multiple-response optimization problem using a multistage approach. The optimization strategy went from actual data correlations, experimental design, computer simulations and surrogate models to a desirability approach that transformed the problem from multiple-objective functions into a single objective function, the overall desirability. The implementation of the double purge system by three Louisiana sugar factories confirmed the reduction of whole color of raw sugar, up to 47%, and the linear relation between double purge magma purity and raw sugar whole color. An overall desirability expression was applied to find the optimal input/output product parameters of the double purge system for different scenarios using JMP® optimization algorithm. Optimal control parameters and recycle determined by this strategy matched the average settings used during actual operation at the 2013 sugarcane crop season. In addition, surrogate models were used to evaluate the importance of the random and control parameters for each response and for each syrup purity scenario. This optimization strategy offers an approach not only to evaluate the importance of several product parameters or the optimal settings, but also offers a better understanding for sugar factory processes and for troubleshooting specific undesired responses. In the future this optimization strategy may be applicable for integrating additional equipment and for improvements of existing process stages at any sugar facilit

    Milk production from leguminous forage, roots and potatoes

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    The aim of the present work was to investigate the effects of replacing grain concentrates with roots and potatoes in dairy cow diets based upon large amounts of grass/alfalfa silage. The emphasis was on the possible improvement of microbial protein synthesis and nitrogen balance. Alfalfa dominated silage has a large excess of ruminally degradable protein that must be balanced with feed carbohydrates to avoid urinary nitrogen losses. The effects on ruminal fermentation pattern, intake and production were also studied. The thesis is based on two batch culture in vitro experiments and three animal experiments. The in vitro experiments compared fodder beets, barley/oats and raw, boiled or frozen potatoes as supplements to a silage diet incubated with rumen fluid from cows fed different diets. With respect to amounts fermented during 5 h incubation, supplements were ranked (P barley/oats > raw potatoes = frozen potatoes = unsupplemented silage. Substrates were numerically ranked in the same order with respect to microbial protein production, but due to larger variation they could only be divided into two groups, where fodder beets, boiled potatoes and barley/oats gave microbial yields not different from each other, but higher than for raw potatoes, frozen potatoes or unsupplemented silage. Butyrate proportion was little affected by incubation substrate but fodder beets fed to rumen fluid donor cows increased butyrate molar proportion in vitro from 10.7 to 13.0%. A change-over design experiment compared barley supplementation with fodder beet and potato supplementation of a silage diet for lactating cows. The fodder beet/potato diet lowered ad libitum silage intake by 0.9 kg DM/d and milk yield decreased correspondingly by 1.7 to 2.3 kg/d. Microbial protein production and nitrogen balance were not increased by the fodder beet supplementation, but a part of N excretion was redirected from urine to feces. Fodder beets tended to decrease the ratio lipogenic/glucogenic VFA, by increasing propionate and butyrate at the expense of acetate. In an intake experiment, most of the cows consumed the maximum allowance of fodder beets (4.6 kg DM/d) while there was a huge variation in the potato intake. A more synchronous feeding of degradable protein and readily available carbohydrates lowered the urinary nitrogen loss and increased allantoin excretion numerically but not significantly. A close correlation (R2 = 0.94) was found between total urinary N excretion and the ratio urea/creatinine in urine, which implies that spot sampling of urine may be a way to facilitate N balance measurements in lactating cows. In conclusion, a full replacement of grain by roots and potatoes can be done and the effects will be lowered urinary N losses but also a reduction in silage consumption and hence also milk production

    A flexible and highly sensitive pressure sensor based on a PDMS foam coated with graphene nanoplatelets

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    The demand for high performance multifunctional wearable devices is more and more pushing towards the development of novel low-cost, soft and flexible sensors with high sensitivity. In the present work, we describe the fabrication process and the properties of new polydimethylsiloxane (PDMS) foams loaded with multilayer graphene nanoplatelets (MLGs) for application as high sensitive piezoresistive pressure sensors. The effective DC conductivity of the produced foams is measured as a function of MLG loading. The piezoresistive response of the MLG-PDMS foam-based sensor at different strain rates is assessed through quasi-static pressure tests. The results of the experimental investigations demonstrated that sensor loaded with 0.96 wt.% of MLGs is characterized by a highly repeatable pressure-dependent conductance after a few stabilization cycles and it is suitable for detecting compressive stresses as low as 10 kPa, with a sensitivity of 0.23 kPa−1, corresponding to an applied pressure of 70 kPa. Moreover, it is estimated that the sensor is able to detect pressure variations of ~1 Pa. Therefore, the new graphene-PDMS composite foam is a lightweight cost-effective material, suitable for sensing applications in the subtle or low and medium pressure ranges
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