scholarly journals Effect of vacuum-drying, hot air-drying and freeze-drying on polyphenols and antioxidant capacity of lemon (Citrus limon) pomace aqueous extracts

2017 ◽  
Vol 52 (4) ◽  
pp. 880-887 ◽  
Author(s):  
Konstantinos Papoutsis ◽  
Penta Pristijono ◽  
John B. Golding ◽  
Costas E. Stathopoulos ◽  
Michael C. Bowyer ◽  
...  
Processes ◽  
2021 ◽  
Vol 9 (8) ◽  
pp. 1309
Author(s):  
Muhammad Heikal Ismail ◽  
Hii Ching Lik ◽  
Winny Routray ◽  
Meng Wai Woo

Fresh rice noodle was usually coated in a large amount of oil to avoid stickiness and extend the shelf life. Pre-treatment has been applied to reduce the quantity of oil in rice noodle. In this research, the pre-treatment and temperature effect on the rice noodle quality subjected to hot air drying, heat pump drying, and freeze drying was investigated. Texture, color, oil content, and starch gelatinization of the dried noodle was further evaluated. Results revealed that there were significant differences (p < 0.05%) in texture, color, oil content, and starch gelatinization in rice noodle subjected to pre-treatment. Furthermore, the texture, color, oil content, and starch gelatinization demonstrated a significant difference (p < 0.05%) in freeze drying rather than hot air drying and heat pump drying. The findings indicate that the qualitative features of the dehydrated noodle are synergistic to pretreatment and drying temperature. Despite superior quality shown by freeze drying, the hierarchical scoring has proven that rice noodle undergoing hot air drying at 30 °C to produce comparable quality attributes. The hierarchical scoring can be a useful tool in quality determination for the food industry.


Molecules ◽  
2021 ◽  
Vol 26 (3) ◽  
pp. 598
Author(s):  
Graziana Difonzo ◽  
Antonella Aresta ◽  
Pietro Cotugno ◽  
Roberta Ragni ◽  
Giacomo Squeo ◽  
...  

Olive pomace is a semisolid by-product of olive oil production and represents a valuable source of functional phytocompounds. The valorization of agro-food chain by-products represents a key factor in reducing production costs, providing benefits related to their reuse. On this ground, we herein investigate extraction methods with supercritical carbon dioxide (SC-CO2) of functional phytocompounds from olive pomace samples subjected to two different drying methods, i.e., freeze drying and hot-air drying. Olive pomace was produced using the two most common industrial olive oil production processes, one based on the two-phase (2P) decanter and one based on the three-phase (3P) decanter. Our results show that freeze drying more efficiently preserves phytocompounds such as α-tocopherol, carotenoids, chlorophylls, and polyphenols, whereas hot-air drying does not compromise the β-sitosterol content and the extraction of squalene is not dependent on the drying method used. Moreover, higher amounts of α-tocopherol and polyphenols were extracted from 2P olive pomace, while β-sitosterol, chlorophylls, and carotenoids were more concentrated in 3P olive pomace. Finally, tocopherol and pigment/polyphenol fractions exerted antioxidant activity in vitro and in accelerated oxidative conditions. These results highlight the potential of olive pomace to be upcycled by extracting from it, with green methods, functional phytocompounds for reuse in food and pharmaceutical industries.


2019 ◽  
Vol 2019 ◽  
pp. 1-11 ◽  
Author(s):  
Lihui Zhang ◽  
Yu Qiao ◽  
Chao Wang ◽  
Li Liao ◽  
Lu Liu ◽  
...  

In this study, freeze vacuum drying (FVD), hot air drying (AD), and FVD combined with AD (FVD-AD) were used to dry kiwifruits. Dried products were analyzed comprehensively on their sensory quality, active components, moisture mobility, odors, and microstructure. Results showed that the FVD-AD saved time by 38.22% compared with FVD while maintaining an acceptable product quality. The antioxidant properties of FVD-AD were lower than those of FVD but significantly higher than those of AD. Moreover, compared with FVD products, FVD-AD products were moderately hard (5252.71 ± 33.53 g) and improved in color, bound water, and microstructure. Additionally, FVD-AD consumed lesser drying time and energy than FD. According to cluster analysis, the odors of FVD-AD products were similar to those of the fresh ones. Principal component analysis of physicochemical and drying cost indicated that FVD-AD was a promising processing technique for functional kiwifruit snacks.


2018 ◽  
Vol 192 ◽  
pp. 03023
Author(s):  
Natthacha Chaloeichitratham ◽  
Pornkanya Mawilai ◽  
Thadchapong Pongsuttiyakorn ◽  
Pimpen Pornchalermpong

In this study, the effects of two drying methods: hot-air and freeze drying for Thai green curry paste in a terms of drying time and qualities have been investigated. The hot-air drying was carried out in tray dryer at temperature of 50, 60 and 70 °C. The freeze drying was carried out in freeze dryer at freezing temperature of -20°C, primary drying temperature of -10°C and secondary drying temperature of 50°C. Moisture content, water activity, colour, bulk density, and total phenolic content (TPC) were determined in samples. Freeze dried sample had significantly (p<0.05) lower moisture content, water activity, bulk density, total colour difference and browning index than hot air dried samples. For antioxidant activity, the results showed hot-air drying at 70°C effected highest TPC similar to freeze drying.


2011 ◽  
Vol 17 (4) ◽  
pp. 319-330 ◽  
Author(s):  
R. Pedreschi ◽  
I. Betalleluz-Pallardel ◽  
R. Chirinos ◽  
C. Curotto ◽  
D. Campos

The influence of different cooking regimes such as boiling, oven, microwave and hot-air drying on the retention of total phenolics (TP), total carotenoids (TC) and in vitro antioxidant capacity (AC) for three colored arracacha roots was studied. Continuous losses of TP, TC and AC during the course of the different cooking processes were observed. Boiling at 99.5° C for 20 min turned to be the best method to cook this root due to a high retention of TP, TC and AC in comparison to oven cooking at 200° C for 45 min and microwave cooking at 800 W for 5 min. During boiling, chlorogenic and caffeic acids and derivatives remained relatively stable. The drying temperature was negatively correlated to the residual content of TP and AC for the yellow and cream arracacha roots, but for the cream/purple arracacha variety, blanching preserved the TP and AC. Significant losses in chlorogenic and caffeic acids and derivatives were mainly observed during hot-air drying. These results suggested that TP are responsible to a large extent of the AC displayed by arracacha root during the different evaluated cooking regimes.


Plants ◽  
2020 ◽  
Vol 9 (12) ◽  
pp. 1792
Author(s):  
Nikola Major ◽  
Bernard Prekalj ◽  
Josipa Perković ◽  
Dean Ban ◽  
Zoran Užila ◽  
...  

The extraction of glucosinolates in boiling aqueous methanol from freeze dried leaf tissues is the most common method for myrosinase inactivation but can be hazardous because of methanol toxicity. Although freeze drying is the best dehydration method in terms of nutritional quality preservation, the main drawbacks are a limited sample quantity that can be processed simultaneously, a long processing time, and high energy consumption. Therefore, the aim of this study is to evaluate the effects of applying high temperature for myrosinase inactivation via hot air drying prior to the extraction step, as well as the effects of cold aqueous methanol extraction on total antioxidant activity, total glucosinolates, total phenolic content, and sugar profile in 36 landraces of kale. The results from our study indicate that cold aqueous methanol can be used instead of boiling aqueous methanol with no adverse effects on total glucosinolate content. Our results also show that hot air drying, compared to freeze drying, followed by cold extraction has an adverse effect on antioxidant activity measured by DPPH radical scavenging, total glucosinolate content, as well as on the content of all investigated sugars.


2012 ◽  
Vol 195-196 ◽  
pp. 441-446
Author(s):  
Jun Liu ◽  
Shi Wei Zhang ◽  
Zhi Jun Zhang

In this paper, the vacuum freeze-drying experiments of both antler slices and whole antlers are reported in details. The moisture content and the eutectic temperature of antler were measured. A 22 h process curve of antler slice freeze drying was obtained. The freeze drying process of whole antler was also investigated. The microscopic tissue structure was observed and chemical compositions were analyzed for those freeze-dried whole antlers in comparison with the traditional water boiling and hot air drying method. More nutrients were retained for freeze drying in addition to the better physical properties than traditional drying.


Sign in / Sign up

Export Citation Format

Share Document