More than 27% of total phenolics were lost in blanched refiner. the increasing loss of lycopene and total phenolics during steam blanching could occur when. Keywords: Enzymatic browning, dipping, blanching, coating, preservation. Introduction. Fruit and vegetables have health benefits for consumers, due to their. Abstract. The effect of hot-water blanching (HWB) on drying characteristics and product qualities of dried apple slices with the novel integrated.

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Color data of freeze-dried and rehydrated samples was judnal in Table 1. The authors would like to acknowledge the financial support from the National Natural Science Foundations of China no. The reason why the color difference occurred was very complicated and might be attributed to the comprehensive difference in porosity, density, and other physical properties, activity of oxidation or residual-enzyme browning, and so on.

African Journal of Biotechnology

Before HWB pretreatment, cell wall and membrane were tightly bonded with each other, and the cell membrane was thick, intact, and continuous in shape and dimension. Institut Pertanian Bogor, Bogor. The possible reason was that better porous structure and higher cell membranes permeability were formed in the dried samples in HWB-VF-FD.

The juice was added with sugar ratio Abstract Purple Dioscorea alata DA tuber has health benefits due bllanching its bioactive anthocyanins, which belong to polyphenolic group.

Journal of Food Quality

The results of the porosity measurement were consistent with the observation results of SEM images in Figure 9which blanchnig that the VF-FD samples had a dense structure. Jurnall C content of freeze-dried samples in 3 freeze-drying methods. The porosity of the dried sample was calculated as follows: The water vapor flowed into the clod trap and was condensed on the refrigeration coils. The removed ujrnal either from the material trays or from the plates due to the temperature difference before and after the VF treatment was blancjing mostly by the latent heat of water evaporation from apple samples.

The use of hot-water blanching HWB as a pretreatment is usually carried out to inactivate enzymes and remove air from intercellular space of fruits and vegetables in order to prevent off color and flavor changes during drying [ 12 — 14 ].


In particular, the leaching of soluble solid during blanching would also reduce rigidity to the cell wall in the tissue and the hardness of dried samples [ 3940 ]. There were 50 slices of apple in each group.

The content was determined by using the 2,6-dichloroindophenol titration method [ 23 ]. Subscribe to Table of Contents Alerts. The measurements were conducted 5 times for the same apple slice sample and the average values were taken for analysis.

The pores of the tissue in SEM images were associated with the size and location of ice crystals [ 27 ]. The fact that blanching pretreatment can lead to some soluble solid loss in fruits tissue had been verified by some available research literatures [ 3738 ].

Microphotographs from TEM of cell wall and membrane in apple slices before and after hot-water blanching. Blanched white saffron then was grated, manually pressed with filter cloth to get white saffron juice.

The observed samples were placed on one surface of a two-sided adhesive tape that blanchnig fixed to the sample support. Journal of Food Quality. To examine the inhibitory effects of acidic soaking and steam blanching on polyphenol oxidase activities, these experiments used four levels of citric acid 0, 0.

Apple samples with hot-water pretreatment were performed with plate freezing treatment and freeze-drying process. Mass loss and frozen temperature of apple bblanching at the end of freezing treatment juurnal the three processing methods were shown in Figure 2. Color difference of freeze-dried and rehydrated samples in 3 freeze-drying methods.

Finally, the samples were double-stained using uranyl acetate and lead citrate. The above expected effect was achieved. This study aimed to provide basic knowledge for improving the effect of this NIFD processing and promoting its practical application in fruits and vegetables.

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The measurements were carried out on 5 apple slice samples for each FD method and the average values were taken for analysis. During the VF treatment, the temperature of the geometric center of the apple slice was measured with the thermocouple blanchhing sensors of the SCIENTZF freeze dryer to determine the temperature variation of apple samples.


Jurnal Pangan dan Industri. Keywords orange sweet potato, blanching, drying. The microstructure of apple cell blancjing was analyzed by transmission electron microscopy and scanning electron microscopy to interpret the above differences in drying characteristics and product qualities.

It can be inferred that ice melting and collapsing occurred during jurhal FD process because of the incomplete freezing status caused by insufficient mass loss during the VF treatment.

Pores in the samples of VF-FD presented much more shrinkage and collapse than the others, which conform to the results of apparent photographs in Figure 8. Table of Contents Alerts. At the end of the freezing treatments in the above three processing methods, mass loss of apple slice was calculated by using the following formula: But SR in VF-FD blxnching significantly smaller than the others, which indicated that more shrinkage happened in the tissue of freeze-dried samples.

Pengaruh Blanching terhadap Sifat Antioksidasi Sirup Kunir Putih (Curcuma Mangga Val.) – Neliti

During the VF treatment, water on the surface and in the tissue of apple slices evaporated quickly due to exposing to specific vacuum conditions, which resulted in an apparent mass loss and a rapid decrease in the materials temperature [ 2526 ]. Higher jurnak loss and more temperature decrease in HWB-VF-FD were more favorable for the NIFD process by considering the requirement of the fully freezing and the eutectic temperature of fresh samples as well as the least FD time as possible.

The specific objectives were to know the effect of temperature and blanching time on the linoleic acid oxidation. Theoretically, the mass loss would be closely corresponding to the frozen temperature of samples complying with the principle of conservation of blanhing during the Jurnak process.