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41.
The surface of meat products during intermittent drying is successively subjected to dehydration and rehydration processes. The aim of this paper was to study the rehydration kinetics at two temperatures (5 and 15 °C) of salted ground pork, (2% or 4% NaCl) dried to different water contents, (10%, 20% and 35%) using Peleg and Weibull’s models. Surface structure of dried samples was analyzed with electron microscopy and related to rehydration kinetics. The equilibrium water content decreased with temperature and increased with NaCl, but was not affected by the initial water content. The rehydration rate at the beginning decreased with water content and was significantly higher at 5 °C than at 15 °C, but it was not significantly affected by NaCl content. However, the equilibrium water decreased with temperature and tended to increase with NaCl content, but was not affected by the initial water content. High level of dehydration resulted in a more damaged and porous meat matrix. This microstructure may contribute to accelerating the rehydration process.  相似文献   
42.
To date, the use of biomarkers has become generally accepted. Biomarker‐driven research has been proposed as a successful method to assess the exposure to xenobiotics by using concentrations of the parent compounds and/or metabolites in biological matrices such as urine or blood. However, the identification and validation of biomarkers of exposure remain a challenge. Recent advances in high‐resolution mass spectrometry along with new analytical (post‐acquisition data‐mining) techniques will improve the quality and output of the biomarker identification process. Chronic or even acute exposure to mycotoxins remains a daily fact, and therefore it is crucial that the mycotoxins’ metabolism is unravelled so more knowledge on biomarkers in humans and animals is acquired. This review aims to provide the scientific community with a comprehensive overview of reported in vitro and in vivo mycotoxin metabolism studies in relation to biomarkers of exposure for deoxynivalenol, nivalenol, fusarenon‐X, T‐2 toxin, diacetoxyscirpenol, ochratoxin A, citrinin, fumonisins, zearalenone, aflatoxins, and sterigmatocystin.  相似文献   
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The mycotoxin deoxynivalenol (DON) is one of the most common mycotoxins of cereals worldwide, and its occurrence has been widely reported in raw wheat. The free mycotoxin form is not the only route of exposure; modified forms can also be present in cereal products. Deoxynivalenol-3-glucoside (DON-3-glucoside) is a common DON plant conjugate. The mycotoxin concentration could be affected by food processing; here, we studied the stability of DON and DON-3-glucoside during baking of small doughs made from white wheat flour and other ingredients. A range of common food additives and ingredients were added to assess possible interference: ascorbic acid (E300), citric acid (E330), sorbic acid (E200), calcium propionate (E282), lecithin (E322), diacetyltartaric acid esters of fatty acid mono- and diglycerides (E472a), calcium phosphate (E341), disodium diphosphate (E450i), xanthan gum (E415), polydextrose (E1200), sorbitol (E420i), sodium bicarbonate (E500i), wheat gluten and malt flour. The DON content was reduced by 40%, and the DON-3-glucoside concentration increased by >100%, after baking for 20 min at 180°C. This confirmed that DON and DON-3-glucoside concentrations can vary during heating, and DON-3-glucoside could even increase after baking. However, DON and DON-3-glucoside are not affected significantly by the presence of the food additives tested.  相似文献   
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The effect of curing salt on the activity of porcine muscle proteases was evaluated, within the salt concentration range found in the manufacturing process of Spanish cured ham. Salt (NaCl) acts as a strong inhibitor of proteolytic activity; sodium nitrate and potassium nitrate do not affect cathepsin D activity; cathepsin L is inhibited at levels of the salts not found in cured ham, and Ca-dependent proteolytic activity is enhanced by nitrate concentrations below 800 ppm.

The appearance of phosphate precipitates in several areas of ham has led to the study of phosphate effect on enzymatic activity. Results show that phosphate is an inhibitor of proteolytic activity.  相似文献   

48.
Brain extraction, also known as skull stripping, is one of the most important preprocessing steps for many automatic brain image analysis. In this paper we present a new approach called Multispectral Adaptive Region Growing Algorithm (MARGA) to perform the skull stripping process. MARGA is based on a region growing (RG) algorithm which uses the complementary information provided by conventional magnetic resonance images (MRI) such as T1-weighted and T2-weighted to perform the brain segmentation. MARGA can be seen as an extension of the skull stripping method proposed by Park and Lee (2009) [1], enabling their use in both axial views and low quality images. Following the same idea, we first obtain seed regions that are then spread using a 2D RG algorithm which behaves differently in specific zones of the brain. This adaptation allows to deal with the fact that middle MRI slices have better image contrast between the brain and non-brain regions than superior and inferior brain slices where the contrast is smaller. MARGA is validated using three different databases: 10 simulated brains from the BrainWeb database; 2 data sets from the National Alliance for Medical Image Computing (NAMIC) database, the first one consisting in 10 normal brains and 10 brains of schizophrenic patients acquired with a 3 T GE scanner, and the second one consisting in 5 brains from lupus patients acquired with a 3 T Siemens scanner; and 10 brains of multiple sclerosis patients acquired with a 1.5 T scanner. We have qualitatively and quantitatively compared MARGA with the well-known Brain Extraction Tool (BET), Brain Surface Extractor (BSE) and Statistical Parametric Mapping (SPM) approaches. The obtained results demonstrate the validity of MARGA, outperforming the results of those standard techniques.  相似文献   
49.
Ultraviolet irradiation has been proved to be effective for inactivating polyphenol oxidase in some fruit derivatives. However, some compounds that may be found in these products, such as melanoidins, can protect the enzyme during the irradiation process. In this piece of work, the protective effect of melanoidins synthesized from fructose and glutamic acid on Agaricus bisporus polyphenol oxidase inactivation by ultraviolet–visible irradiation has been assessed. The polymers with molecular mass lower than 150 kDa had a greater protective effect than those molecules higher than 150 kDa. If the obtained melanoidins are not fractioned by their molecular mass, the protective effect that they exert is lower. It was found that the most effective radiation to inactivate this polyphenol oxidase is that between 260 and 310 nm.  相似文献   
50.
This paper addresses visual object perception applied to mobile robotics. Being able to perceive household objects in unstructured environments is a key capability in order to make robots suitable to perform complex tasks in home environments. However, finding a solution for this task is daunting: it requires the ability to handle the variability in image formation in a moving camera with tight time constraints. The paper brings to attention some of the issues with applying three state of the art object recognition and detection methods in a mobile robotics scenario, and proposes methods to deal with windowing/segmentation. Thus, this work aims at evaluating the state-of-the-art in object perception in an attempt to develop a lightweight solution for mobile robotics use/research in typical indoor settings.  相似文献   
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