Summary Three different combined microwave (MW) drying methods were compared, namely microwave‐assisted vacuum (MWVD), freeze (MWFD), microwave‐enhanced spouted bed (MWSD), in terms of rate, uniformity, product colour, rehydration ratio, retention β ‐ carotene and vitamin C, energy consumption. The rate MWVD MWSD much faster than that MWFD. largest was obtained with 3.5 W g −1 . In general, the colour products very uniform. Rehydration ratio MWFD carrot pieces almost same as freeze‐dried...

Diverse types of vegetable snacks made using different drying methods are becoming increasingly commercially important for the food processing industry worldwide because they also recognized as healthy human consumption. Here we consider four aspects snacks: unit operations currently used in industry, novel or emerging with nontraditional means, combined (or hybrid) methods, and quality changes during storage. Each method has its own advantages limitations. Hybrid techniques being developed...

Apple slices dried by two combination drying methods and freeze-drying (FD) were evaluated for their composition analyzed texture, aroma microstructure. FD followed microwave vacuum (FD + MWVD) yielded samples of higher reducing sugars, total pectin lower phenols comparing to samples. On the other hand, MWVD had than whole, retention in is better products worse Moreover, crispness was hardness Microwave application a significant effect on phenols, aroma. In addition, longer time high...

The shape, color, flavor, and rehydration capacity of freeze-dried (FD) products are all better than other dried products. However, the energy consumption during FD is very high, which limits application this drying method for common materials. In article, microwave vacuum (MWVD) was applied before or after to decrease FD. Moreover, divided into two parts: valid invalid consumption. Apple slices were used as an example calculate saving percentage by comparing combination with freeze 8.28 h...

ABSTRACT Three different drying methods, microwave-spouted bed (MSBD), microwave-vacuum (MVD) and hot air (AD), were used to dry diced sweet potato. The characteristics product quality are discussed in terms of the kinetics, rehydration ratio, expansion breaking force (crispness), color retention β-carotene. As expected, rates MSBD MVD much faster than that obtained AD; largest rate was with 2.5 W/g microwave (MW) power level. products dried using displayed good puffing: ratios about 2.0...

In this study, Fuji apple slices were dehydrated using freeze drying (FD) combined with microwave assisted vacuum (VMD). The optimal parameter for the diversion point of moisture content from FD to VMD process was at level 21%, and pressure 9.15 kPa power density a 3.18 w/g. results show that two-step technique can significantly reduce total time required by up 40%, while nutritional value dried chips remained unchanged compared used alone.

Abstract BACKGROUND: In commercial deep‐fat frying of potato chips, the oil content final products ranges from 35 to 45 g 100 −1 (wet basis). High‐temperature may cause formation acrylamide, making unhealthy consumer. The aim this research was explore a new method, spouted bed microwave drying, produce healthier puffed snack cubes as possible alternatives oil‐fried chips. influence drying conditions on puffing characteristics were studied and compared with direct hot air method. RESULTS:...

The effects of microwave heating on the molecular arrangements in potato starch, including single and double helices amorphous structures, were studied using a ¹³C CP/MAS NMR method combined with X-ray diffraction.

In this study, terahertz time-domain spectroscopy (THz-TDS) was proposed to identify coffee of three different varieties and roasting degrees one variety. Principal component analysis (PCA) applied extract features from frequency-domain spectral data, the extracted were used for classification prediction through linear discrimination (LD), support vector machine (SVM), naive Bayes (NB), k-nearest neighbors (KNN). The effect misclassification model analyzed via confusion matrix. varieties,...

Carbon-centred radicals are revealed in the microwave treated rice protein samples. The change of structure a field is often presumed to be caused by free radicals.

The effect of non-ionizing microwave radiation on starch is due to a gelatinization temperature range that changes structure and properties. However, the in upon heating are observable throughout process. We compared effects by microwaves rapid regular conventional heating. Our results show promotes rearrangement molecules at low temperatures; showed stable dielectric response high constant. Microwave changed Cole-Cole curve polarization suspension temperatures. A marked transition 2.45 GHz...

Abstract The drying quality of kiwifruit dried by a combination freeze and microwave vacuum (FD‐MVD) in terms time, appearance microstructure. results showed that the FD‐MVD products was highest with FD 12 h because lowest volume density close to color single samples. optimal power for MVD process found be 0.30 W/g. microstructure 8 samples maintained very well due whole cell structure between center edge kiwifruit. This is moisture content at edges centers identical h. However, 10 h,...

Metal–organic frameworks (MOFs) are potentially useful in addressing challenges food chemistry light of their tunable pore dimensions and functionalities. Here we demonstrate the adsorption release 1-methylcyclopropene (1-MCP) by easily attainable microporous MOFs. The effectiveness encapsulation system has been validated a fruit preservation test.

A batch-type microwave vacuum dryer was used to study the effects of different power densities on drying characteristics and quality whole lychee (Litchi chinensis Sonn.) fruits. Lychees were treated at levels it observed that process included two stages when density above 0.3 W/g, consisted three 0.1 W/g. The optimal found be 0.6 typical pulp temperature profile lychees during (MVD), including four stages: increasing, decreasing, gently increasing sharply increasing. Moreover, decrease in...

In the food industry, research into characteristics of microwave-heated materials has focused on dielectric properties. However, lack studies microwave-absorbing properties hindered application microwave technology. The aim present study was to investigate rice starch. It should be noted that this first time improved arch method used measure reflection loss (RL) starch dispersion. results showed absorption liquid system corresponded classical quarter-wavelength resonator model. When...

The quality of freeze drying (FD)4.5 h-microwave vacuum (MVD) iron yam slices was almost the same with FD samples in terms bulk density, color, etc., previous experiments. This work verified it by comparing microstructure samples. In addition, and different conversion point during combined MVD were tested order to illuminate change mechanism for cell structure relationship between corresponding quality. Moisture melting significantly affected dried FD3.5 h-MVD maintained very well. However,...

Effect of air drying and freeze on polysaccharides lychee with three cultivars was determined in terms yield, antioxidant capacity hypoglycemic action. The results show that Guiwei pulp had the highest crude polysaccharide yield among lychees. However, Feizixiao lowest EC50 concentration FRAP (Ferric reducing power) value. Moreover, lychees dried by best effect for improving glucose tolerance normal mice diabetic mice. Three no significant effect. samples decreasing TG it even better than...