Drying Performance and Product Quality of Sliced Carrots by Infrared Blanching Followed by Different Drying Methods

Abstract The objective of this study was to investigate the processing parameters and quality of carrots under sequential infrared (IR) dry-blanching and (1) hot air drying (IRB-HAD), (2) infrared drying (IRB-IRD), and (3) Infrared-hot air drying (IRB-IRHAD). Water blanching at 90oC was used for comparison. The quality of dried carrot was evaluated based on vitamin C content, rehydration ratio, color, shrinkage and hardness. Applying IR dry-blanching for 15 min resulted in the reductions of about one log in peroxidase (POD) activities and 54 % in moisture reduction. A notable change in the surface color and retention of vitamin C were obtained with IR blanching. IRB-IRD and IRB-IRHAD had higher drying rates and higher quality. The recommended processing parameters for IRB-IRHAD are IR blanching for 15 min, followed by IR drying to a moisture content of 30–40 % wet basis (w.b.), and then finished by HA drying to a targeted MC (8 % w.b.).

Download Full-text

Effects of drying methods on color retention and chlorophyll of celery (ApiumgraveolensL.), spinach (Spinacia oleraceaL.), Malabar spinach (Basella albaL.)

The Journal of Agriculture and Development ◽

10.52997/jad.6.06.2020 ◽

2020 ◽

pp. 53-61

Author(s):

Dat Q Tran

Keyword(s):

Microwave Drying ◽

Drying Methods ◽

Hot Air Drying ◽

Drying Time ◽

Air Drying ◽

Color Retention ◽

Hot Air ◽

Drying Techniques ◽

Dried Vegetables

Dried vegetables are considered convenient for storage, transportation and preservation. The different drying techniques could influence the quality of resulting products. This study aimed to evaluate the effects of three distinguish drying methods as hot-air drying, foam-mat drying and microwave drying on the color retention and chlorophyll of green vegetables powder. Fresh spinach(Spinacia oleraceaL.), celery (Apium graveolensL.), Malabar spinach (Basella albaL.) were dried by different methods: hot air at 60oC, foam-mat at 60oC and microwave at 270 W until the samples reached approximately 9% of moisture content (wb). The drying time of the dried samples by microwave, foam-mat and hot-air method were 60, 210 and 240 min, respectively. Foam-mat dried vegetables were found to have the best quality in terms of color and the residual chlorophyll content. The findings suggest that foam-mat drying is promising in dried vegetable processing

Download Full-text

Effect of Hot Air Thin Layer Drying Temperature on Physicochemical and Textural Properties of Dried Horseradish

Journal of Food Industry ◽

10.5296/jfi.v3i1.15721 ◽

2019 ◽

Vol 3 (1) ◽

pp. 1

Author(s):

Pranabendu Mitra ◽

Md. Abdul Alim ◽

Venkatesh Meda

Keyword(s):

Textural Properties ◽

Drying Method ◽

Rehydration Ratio ◽

Hot Air Drying ◽

Air Drying ◽

Medicinal Uses ◽

Drying Temperature ◽

Hot Air ◽

Thin Layer Drying

The horseradish (Armoracia rusticana) is an important crop as ingredients for many commercial food products and medicinal uses. However, the horseradish is perishable and preservation of this crop for supplying year-round is necessary. Drying can be used to preserve the horseradish but establishing a suitable drying method and conditions are important for product quality of dried horseradish. The objective of this study was to investigate the effects of hot air-drying temperatures on the physicochemical and textural properties of dried horseradish samples to determine the appropriate hot air-drying conditions. The sliced horseradish samples were dried at 55, 65, 75, 85 and 95 ℃ using a conventional hot air drier. The physicochemical and textural properties of the dried horseradish samples were determined, and the results were compared for different drying temperatures. The ANOVA analysis indicated that the drying temperature affected the physicochemical and textural properties of dried horseradish samples significantly (p<0.05). The experimental results indicated that the moisture content (9.18-6.15%,wb), aw (0.06-0.03), porosity (31.47-12.13%) and rehydration ratio (82.74 -44.47%) decreased and piece density (0.63-0.84 g/mL), hardness (193.63 -298.31N), cohesiveness (1.04-1.32), gumminess (202.13-390.12) and chewiness (635.08-1223.55) of dried horseradish samples increased with the drying temperature. Power law model indicated that the porosity was linearly corelated to the rehydration ratio of dried horseradish samples. The overall results revealed that relatively lower (55-65 ℃) drying temperature range was suitable to keep the quality of the dried horseradish samples. The findings of this study are expected to be helpful for the commercial drying of horseradish samples using hot air-drying method.

Download Full-text

Effect of freeze drying and hot air drying methods on quality of cordycepin production

MATEC Web of Conferences ◽

10.1051/matecconf/201819203001 ◽

2018 ◽

Vol 192 ◽

pp. 03001

Author(s):

Thitiphan Chimsook

Keyword(s):

Freeze Drying ◽

Low Cost ◽

Bioactive Compound ◽

Raw Material ◽

Total Phenolic ◽

Drying Methods ◽

Hot Air Drying ◽

Air Drying ◽

Hot Air

This study determined the effect of drying methods including hot air drying and freeze drying on the quality of cordycepin production from Cordyceps militaris. The fruiting bodies and mycelium of C. militaris were used as the raw material. For hot air drying was performed at 55 °C for 24 hrs. Whereas the freeze drying was carried out under vacuum at 140 L min-1 for 48 hours. The bioactive compound extracted from dried powder of C. militaris from two drying methods was investigated. The results showed that both cordycepin and adenosine extracted from freezed drying sample had higher value than those of extracted from hot air dried sample. The bioactivities of C. militaris extract were investigated. The results revealed that the antioxidant activity and also total phenolic contents of C. militaris extract prepared from freeze drying had higher value than that of extracted from hot air drying. However, most of C. militaris production performed using hot air drying to dry sample because of its low cost technique.

Download Full-text

Drying Kinetics and Quality of Whole, Halved, and Pulverized Tiger Nut Tubers (Cyperus esculentus)

International Journal of Food Science ◽

10.1155/2021/8870001 ◽

2021 ◽

Vol 2021 ◽

pp. 1-11

Author(s):

Ernest Ekow Abano ◽

Joshua Akanson ◽

Nazir Kizzie-Hayford

Keyword(s):

Vitamin C ◽

Reducing Sugars ◽

Dry Weight ◽

Drying Kinetics ◽

Hot Air Drying ◽

Air Drying ◽

Hot Air ◽

Drying Conditions ◽

Tiger Nuts

The objective of this study was to provide the optimum drying conditions to produce high-quality dried tiger nuts using hot-air drying. For this, we evaluated the effect of the whole, halved, and pulverized tiger nuts and air temperature (50 to 70°C) on the drying kinetics and quality of tiger nuts. The drying process generally followed a constant rate in the first 3 hours and a falling regime. We found the optimum drying conditions for tiger nuts to be crushed before convective hot-air drying at a temperature of 70°C. At this optimum condition, the predicted drying time, vitamin C content, reducing sugars, browning, brightness, redness, and yellowness was 780 min, 22.9 mg/100 mg dry weight, 157.01 mg/100 g dry weight, 0.21 Abs unit, 56.97, 1.6, and 17.0, respectively. The tiger nut’s reducing sugars increased from the 130.8 mg/100 dry weight in the raw tiger nuts to between 133.11 and 158.18 mg/100 dry weight after drying. The vitamin C degradation rate was highest in the uncut tiger nuts (32-35%) while in the halved and the pulverized samples, it was between 12 and 17%. The crushed samples’ effective moisture removal increased between 5.6- and 6.75-fold at the different air temperatures than that of the intact tiger nuts. The activation energy was 18.17 kJ/mol for the unbroken, 14.78 kJ/mol for the halved, and 26.61 kJ/mol for the pulverized tiger nut samples. The model MR = 0.997 exp − 0.02 t 1.266 + 0.0000056 t was the most suitable thin-layer drying model among the models examined for convective hot-air drying of tiger nuts. It is advisable to crush tiger nut before hot-air drying to produce better-quality flour for making milk beverages, cakes, biscuits, bread, porridge, and tiger nut-based breakfast cereals.

Download Full-text

Effect of Drying Methods on Yield and Quality of the Avocado Oil

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.735.127 ◽

2017 ◽

Vol 735 ◽

pp. 127-131 ◽

Cited By ~ 3

Author(s):

Thitiphan Chimsook ◽

Rittichai Assawarachan

Keyword(s):

Fatty Acids ◽

Unsaturated Fatty Acids ◽

Saturated Fatty Acids ◽

Raw Material ◽

Drying Methods ◽

Hot Air Drying ◽

Air Drying ◽

Hot Air ◽

Avocado Oil

This experimental study was carried out to verify the quality enhancement of avocado oil production by different drying methods. During this study, samples of green avocado cake were obtained from Tak Province, Thailand. The small size of fresh green avocados was the raw material to prepare the high quality of avocado oil. The drying methods composed of air drying, hot air drying and vacuum drying, respectively. The dried avocado pulp was evaluated the moisture contents and then pressed avocado oil using the extraction machine. All avocado oil were determined the physical and chemical properties. The current study revealed that hot air drying and air drying had the highest and lowest yield, respectively. The unsaturated fatty acids in avocado oil were higher than the saturated fatty acids in all avocado oils from the three drying methods. The costs of drying methods were considered and the present study revealed that the best method for drying green avocado cake was hot air drying with the desired oven.

Download Full-text

Supercritical CO2 Extraction of Phytocompounds from Olive Pomace Subjected to Different Drying Methods

Molecules ◽

10.3390/molecules26030598 ◽

2021 ◽

Vol 26 (3) ◽

pp. 598

Author(s):

Graziana Difonzo ◽

Antonella Aresta ◽

Pietro Cotugno ◽

Roberta Ragni ◽

Giacomo Squeo ◽

...

Keyword(s):

Olive Oil ◽

Freeze Drying ◽

Oil Production ◽

Production Costs ◽

Drying Methods ◽

Olive Pomace ◽

Hot Air Drying ◽

Air Drying ◽

Hot Air ◽

Pharmaceutical Industries

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.

Download Full-text