Evaluation of the effect of processing on cocoa polyphenols: antiradical activity,anthocyanins and procyanidins profiling from raw beans to chocolate

The content and composition of anthocyanins and procyanidins in fermented cocoa beans (from different geographic origins: Ecuador, Cameroon, Ivory Coast, Ghana and Nigeria), roasted nibs, cocoa mass and chocolate were determined, beside the determination of the total antiradical capacity. Concerning geographic origin, cocoa beans and processed products from Ecuador showed the highest levels of anthocyanins, followed by Nigeria and Cameroon. Generally, as cocoa beans were further processed, the levels of anthocyanins and flavan‐3‐ols decreased. The largest observed losses of phenolics occurred during roasting. A progressive decreasing trend in polyphenol concentration was observed in the other processed samples as well. Despite the original content of polyphenols in raw cocoa beans, technological processes imply a significant impact on cocoa quality, confirming the need of specific optimisation to obtain high value chocolate.     

Shelf Life of Minimally Processed Honeydew, Kiwifruit, Papaya, Pineapple and Cantaloupe

This study was to determine the shelf life of minimally processed honeydew melon, kiwifruit, papaya, pineapple, and cantaloupe stored at 4°C. Sensory assessments were carried out at 3-day intervals by highly trained panels until the end of shelf life. Microbiological counts were made immediately after dicing fruit and at the end of shelf life. Results indicated that both the length of shelf life and type of spoilage were related to fruit species. Minimally processed fruit had longer shelf life at 4°than at temperatures recommended for whole fruit when these were greater than 4°C. Spoilage of 4°C-stored kiwifruit, papaya and pineapple pieces was not a consequence of microbial growth.     

应用西门子840D系统数控铣镗床的电气设计

本文阐述了数控铣镗床PLC程序设计方法和思路．并就用户特定机床面板PLC程序设计及用平旋盘实现铣镗、车复合加工的电气设计作了详细描述?     

Development of flexible displays using back‐channel‐etched In–Sn–Zn–O thin‐film transistors and air‐stable inverted organic light‐emitting diodes

We developed flexible displays using back‐channel‐etched In–Sn–Zn–O (ITZO) thin‐film transistors (TFTs) and air‐stable inverted organic light‐emitting diodes (iOLEDs). The TFTs fabricated on a polyimide film exhibited high mobility (32.9 cm²/Vs) and stability by utilization of a solution‐processed organic passivation layer. ITZO was also used as an electron injection layer (EIL) in the iOLEDs instead of conventional air‐sensitive materials. The iOLED with ITZO as an EIL exhibited higher efficiency and a lower driving voltage than that of conventional iOLEDs. Our approach of the simultaneous formation of ITZO film as both of a channel layer in TFTs and of an EIL in iOLEDs offers simple fabrication process.     

pH influences hydrolysis of sodium polyphosphate in dairy matrices and the structure of processed cheese

We investigated the effect of pH (5.2 to 6.8) on the hydrolysis of a sodium polyphosphate in water, milk, calcium caseinate, and spreadable processed cheese, as well as the effect of pH on the cheese structure. Monitoring of the hydrolysis in water and the different milk matrices was carried out using ³¹P nuclear magnetic resonance technique. In general, the decrease in pH increased the hydrolysis of polyphosphates in all matrices. The presence of calcium in milk increased the rate of hydrolysis. Hydrolysis in milk was higher than in calcium caseinate, probably due to lower molecular mobility in concentrated systems with high viscosity. Increasing the pH decreased the hardness and adhesiveness of the cheeses. At low pH (5.2 and 5.6), the cheeses presented a granular structure, although, at more neutral pH (6.0 to 6.8), the structure was continuous, homogeneous, and more fluid. These results highlight the importance of precise pH control in the manufacture of processed cheeses.     

Postharvest performance of fresh‐cut ‘Big Top’ nectarine as affected by dipping in chemical preservatives and packaging in modified atmosphere

Fresh‐cut ‘Big Top’ nectarines were dipped in 2% (w/v) ascorbic acid–1% (w/v) calcium lactate and stored at 4 °C for up to 12 days in 10 kPa O₂‐ and 10 kPa CO₂‐modified atmosphere packaging (MAP). The used microperforated plastic film allowed O₂ and CO₂ concentrations to reach steady values from the fifth day in storage onwards. Samples stored in MAP after chemical dipping showed the highest visual quality score, slight browning symptoms, increment in firmness and very low ethanol and acetaldehyde content. The chemical dipping also increased antioxidant capacity, probably due to the effect of ascorbic acid. The results suggested that the control of yeasts was mainly exerted by MAP, whereas only a slight effect was achieved by the chemical dipping. Therefore, MAP plus ascorbic acid/calcium lactate dipping was the best combination to preserve phytochemical content, antioxidant capacity and microbiological safety of fresh‐cut nectarines during storage.     

Strategies toward High‐Performance Solution‐Processed Lateral Photodetectors

Due to their low cost and ease of integration, solution‐processed lateral photodetectors (PDs) are becoming an important device type among the PD family. In recent years, enormous effort has been devoted to improving their performances, and great achievements have been made. A summary of the core progress, especially from the perspective of design principles and device physics, is necessary to further the development of the field, but is currently lacking. Here, to address this need, first, the working mechanism of PDs and the device figures‐of‐merit are introduced. Second, by classifying the active materials into four categories, including inorganic, organic, hybrid, and perovskite, the developed strategies toward high performance are discussed respectively. To close, the common physical rules behind all these strategies are generalized, and suggestions for future development are given accordingly.     

Extraction and reliable determination of acrylamide from thermally processed foods using ionic liquid-based ultrasound-assisted selective microextraction combined with spectrophotometry

Acrylamide (AAm) is a carcinogenic chemical that can form in thermally processed foods by the Maillard reaction of glucose with asparagine. AAm can easily be formed especially in frequently consumed chips and cereal-based foods depending on processing conditions. Considering these properties of AAm, a new, simple and green method is proposed for the extraction of AAm from thermally processed food samples. In this study, an ionic liquid (1-butyl-3-methylimidazolium tetrafluoroborate, [Bmim][BF₄]) as extractant was used in the presence of a cationic phenazine group dye, 3,7-diamino-5-phenylphenazinium chloride (PSH⁺, phenosafranine) at pH 7.5 for the extraction of AAm as an ion-pair complex from selected samples. Under optimum conditions, the analytical features obtained for the proposed method were as follows; linear working range, the limits of detection (LOD, 3S_b/m) and quantification (LOQ, 10S_b/m), preconcentration factor, sensitivity enhancement factor, sample volume and recovery% were 2.2–350 µg kg^?1, 0.7 µg kg^?1, 2.3 µg kg^?1, 120, 95, 60 mL and 94.1–102.7%, respectively. The validity of the method was tested by analysis of two certified reference materials (CRMs) and intra-day and inter-day precision studies. Finally, the method was successfully applied to the determination of AAm levels in thermally processed foods using the standard addition method.     

改善加热不燃烧型烟草薄片物理性能的研究

加热不燃烧型烟草薄片是一种新型烟草薄片,其制备方法主要包括稠浆法、辊压法、造纸法。为保证烟草薄片的良好成形及耐加工性,需添加一定量的木浆纤维。本研究探究了木浆纤维在稠浆法加热不燃烧型烟草薄片中的应用,考察了木浆纤维打浆度和添加量对稠浆性能和烟草薄片物理性能的影响。研究表明,增加木浆纤维打浆度有利于降低稠浆黏度,木浆纤维的打浆度为49 °SR时,烟草薄片的力学性能相对较好;木浆纤维添加量在2%~5%时,烟草薄片力学强度随着木浆添加量的增加而增加,抗张指数最高可达3.62 N·m/g。     

辐照技术在猪肉加工制品中的应用

详细阐述了辐照技术对猪肉加工制品的感官和成品中的蛋白质、脂肪和碳水化合物等成分的影响.并对辐照技术在猪肉加工制品中,延长保存期和安全性等关键作用方面做了论述.用10kGy以下辐照剂量处理过的食品,其风味、色泽,内部的蛋白质、脂肪和维生素等基本保持稳定,同时可以有效地延长猪肉加工制品的保存期.