Effect of Hot Air, Microwave and Freeze Drying on Drying Characteristics of Button Mushroom Slices (Agaricus bisporus)

Aims: Button mushrooms, rich in vitamins and minerals, are very highly perishable and therefore, it has been very necessary to develop a value-added product. The aim of the research work is to study the effects of blanching on air-dried, microwave oven dried, and freeze dried mushroom samples and also to study the characterization of dried samples. Place and Duration of Study: Department of Agricultural Engineering, School of Agricultural and Bio-Engineering, Centurion University of Technology & Management, between February 2021 to June 2021 Methodology: Three different drying techniques like hot air, microwave, and freeze drying were taken to study the drying effect on dried mushroom slices. The quality parameters like dehydration and rehydration potential, density, ascorbic acid, color, and organoleptic properties were studied. Results: The rehydration ratio of freeze dried mushroom samples were high having low density than the other dried samples. Less color deterioration was also found in freeze drying. Moreover, ascorbic acid, color, texture, and overall acceptability of sensory analysis were found to be maximum in freeze dried samples. The freeze dried product was found to be attractive in flavour and texture and got highest score in sensory analysis. Conclusion: The freeze drying can be an effective drying method to dry fresh mushroom compared to hot air and microwave drying.

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Effect of Drying on the Bioactive Compounds and Antioxidant Activity of Rubus lambertianus

International Journal of Food Engineering ◽

10.1515/ijfe-2016-0412 ◽

2018 ◽

Vol 14 (2) ◽

Author(s):

Jun Yu ◽

Zijian Shangguan ◽

Xingju Yang ◽

Dan Sun ◽

Baoqing Zhu ◽

...

Keyword(s):

Bioactive Compounds ◽

Freeze Drying ◽

Antioxidant Activities ◽

Drying Methods ◽

Protective Effects ◽

Red Raspberry ◽

Hot Air Drying ◽

Hot Air ◽

Freeze Dried ◽

Total Anthocyanins

AbstractDifferent drying methods, including hot air drying (HAD), freeze drying (FD), spray drying and vacuum drying (VD), were investigated to determine their influence on the chromatic coordinates, phenolics, anthocyanins and antioxidant activities of dried red raspberry (Rubus lambertianus). Pelargonidin-3-O-glucoside and catechin were found to be the main anthocyanin and non-anthocyanin phenolics, respectively, in fresh red raspberry. The most effective method for controlling browning was FD. The highest protective effects against bioactive compounds were observed in freeze-dried powders, when measuring the total anthocyanins, the scavenging of DPPH (1,1-diphenyl-2-picrylhydrazyl) and hydroxyl radicals and the inhibition effects on lard oxidation. HAD was effective for the preservation of total phenolics, while VD was useful for protecting catechin and procyanidin B1.

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Effect of Drying Process, Encapsulation, and Storage on the Survival Rates and Gastrointestinal Resistance of L. salivarius spp. salivarius Included into a Fruit Matrix

Microorganisms ◽

10.3390/microorganisms8050654 ◽

2020 ◽

Vol 8 (5) ◽

pp. 654

Author(s):

Ester Betoret ◽

Noelia Betoret ◽

Laura Calabuig-Jiménez ◽

Cristina Barrera ◽

Marco Dalla Rosa

Keyword(s):

Survival Rate ◽

Physicochemical Properties ◽

Freeze Drying ◽

Molecular Mechanisms ◽

Survival Rates ◽

In Vitro Digestion ◽

Hot Air ◽

Freeze Dried ◽

And Storage

In a new probiotic food, besides adequate physicochemical properties, it is necessary to ensure a minimum probiotic content after processing, storage, and throughout gastrointestinal (GI) digestion. The aim of this work was to study the effect of hot air drying/freeze drying processes, encapsulation, and storage on the probiotic survival and in vitro digestion resistance of Lactobacillus salivarius spp. salivarius included into an apple matrix. The physicochemical properties of the food products developed were also evaluated. Although freeze drying processing provided samples with better texture and color, the probiotic content and its resistance to gastrointestinal digestion and storage were higher in hot air dried samples. Non-encapsulated microorganisms in hot air dried apples showed a 79.7% of survival rate versus 40% of the other samples after 28 days of storage. The resistance of encapsulated microorganisms to in vitro digestion was significantly higher (p ≤ 0.05) in hot air dried samples, showing survival rates of 50–89% at the last stage of digestion depending on storage time. In freeze dried samples, encapsulated microorganisms showed a survival rate of 16–47% at the end of digestion. The different characteristics of the food matrix after both processes had a significant effect on the probiotic survival after the GI digestion. Documented physiological and molecular mechanisms involved in the stress response of probiotic cells would explain these results.

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Freeze-Drying Investigations of Antlers

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.195-196.441 ◽

2012 ◽

Vol 195-196 ◽

pp. 441-446

Author(s):

Jun Liu ◽

Shi Wei Zhang ◽

Zhi Jun Zhang

Keyword(s):

Freeze Drying ◽

Eutectic Temperature ◽

Tissue Structure ◽

Chemical Compositions ◽

Drying Method ◽

Drying Process ◽

Hot Air Drying ◽

Air Drying ◽

Hot Air ◽

Freeze Dried

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.

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Pressurized Extraction as an Opportunity to Recover Antioxidants from Orange Peels: Heat treatment and Nanoemulsion Design for Modulating Oxidative Stress

Molecules ◽

10.3390/molecules26195928 ◽

2021 ◽

Vol 26 (19) ◽

pp. 5928

Author(s):

Lucía Castro-Vázquez ◽

María Victoria Lozano ◽

Virginia Rodríguez-Robledo ◽

Joaquín González-Fuentes ◽

Pilar Marcos ◽

...

Keyword(s):

Freeze Drying ◽

Value Added ◽

Orange Peel ◽

Natural Antioxidants ◽

Volatile Components ◽

Orange Peels ◽

Freeze Dried ◽

Food Applications ◽

By Products ◽

Terpene Derivatives

Orange peel by-products generated in the food industry are an important source of value-added compounds that can be potentially reused. In the current research, the effect of oven-drying (50–70 °C) and freeze-drying on the bioactive compounds and antioxidant potential from Navelina, Salustriana, and Sanguina peel waste was investigated using pressurized extraction (ASE). Sixty volatile components were identified by ASE-GC-MS. The levels of terpene derivatives (sesquitenenes, alcohols, aldehydes, hydrocarbons, and esters) remained practically unaffected among fresh and freeze-dried orange peels, whereas drying at 70 °C caused significative decreases in Navelina, Salustriana, and Sanguina peels. Hesperidin and narirutin were the main flavonoids quantified by HPLC-MS. Freeze-dried Sanguina peels showed the highest levels of total-polyphenols (113.3 mg GAE·g−1), total flavonoids (39.0 mg QE·g−1), outstanding values of hesperedin (187.6 µg·g−1), phenol acids (16.54 mg·g−1 DW), and the greatest antioxidant values (DPPH•, FRAP, and ABTS•+ assays) in comparison with oven-dried samples and the other varieties. Nanotechnology approaches allowed the formulation of antioxidant-loaded nanoemulsions, stabilized with lecithin, starting from orange peel extracts. Those provided 70–80% of protection against oxidative UV-radiation, also decreasing the ROS levels into the Caco-2 cells. Overall, pressurized extracts from freeze-drying orange peel can be considered a good source of natural antioxidants that could be exploited in food applications for the development of new products of commercial interest.

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Evaluation of physico-chemical properties of tomato powder produced by an optimized freeze drying process

International Journal of Food Engineering ◽

10.1515/ijfe-2020-0046 ◽

2021 ◽

Vol 0 (0) ◽

Author(s):

Zeyu Wu ◽

Haiyan Wang ◽

Li Zhang ◽

Zhaojun Xian ◽

Honghong Li ◽

...

Keyword(s):

Ascorbic Acid ◽

Freeze Drying ◽

Binding Capacity ◽

Chemical Properties ◽

Soluble Solids ◽

Drying Process ◽

Total Acid ◽

Physico Chemical ◽

Freeze Dried ◽

Tomato Powder

Abstract In this study, the physico-chemical properties of tomato powder produced by an optimized freeze drying process (FDP) were evaluated. With the lycopene content as the dependent variable, the optimum FDP conditions (i.e., thermal cracking time of 62 s, ascorbic acid addition amount [0.13%], and particle size [Dv90] of 163 μm) were obtained through response surface methodology (RSM). The results showed that the content of lycopene in the prepared tomato powder was higher than that in two commercial products. Aldehydes were the main components among 25 kinds of aromatic substances detected in tomato powder. The values of a * and a */b *, the hydration properties including water holding capacity (WHC) and oil binding capacity (OBC), and the content of total acid, ascorbic acid, and soluble solids were improved compared to commercial spray dried and freeze dried samples. All the above results suggested that FDP was an adequate procedure for the production of high-quality tomato powder.

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Physical, Microbial, and Chemical Quality of Hot-Air-Dried Persimmon (Diospyros kaki) Chips during Storage

Journal of Food Quality ◽

10.1155/2020/7413689 ◽

2020 ◽

Vol 2020 ◽

pp. 1-15 ◽

Cited By ~ 1

Author(s):

Rebecca R. Milczarek ◽

Ana M. Vilches ◽

Carl W. Olsen ◽

Andrew P. Breksa ◽

Bruce E. Mackey ◽

...

Keyword(s):

Ascorbic Acid ◽

Value Added ◽

Diospyros Kaki ◽

Chemical Quality ◽

Entire Study ◽

Persimmon Fruit ◽

Hot Air ◽

A Value ◽

Met Pet

Recent efforts have been made to develop hot-air-dried chips as a value-added product for persimmon fruit (Diospyros kaki). However, the long-term quality of this product and its dependence on processing conditions and packaging type have not yet been explored. Hence, in this work, chips were prepared from “Hachiya” persimmon fruit in 2 ways: 2 mm thickness fruit slices, hot-air-dried for 5 hours (Preparation 2–5), and 6 mm slices, dried for 10 hours (Preparation 6–10). The dried chips were then packaged into 2 bag types (plastic zip-top and metallized polyethylene terephthalate (Met-PET) with desiccant packets), stored under ambient conditions, and sampled for moisture-related, microbial, texture, and chemical quality traits throughout the 1-year storage study. It was found that–with the exception of a marked decrease in ascorbic acid (vitamin C)—all 4 Preparation/Packaging combinations yielded products that maintained acceptable color, microbial, nutritional, and textural quality throughout the entire study. Compared to Preparation 2–5 chips, Preparation 6–10 chips generally had lower contents of healthy nutrients—antioxidant compounds, ascorbic acid, and carotenoids. Evidence of invertase activity was found for Preparation 6–10 chips but not for Preparation 2–5 chips. For both preparations, the contents of ascorbic acid and carotenoids experienced time-dependent decreases. Plastic zip-top bags and Met-PET bags with desiccant packets performed equally well as packaging for most of the quality metrics tracked during this study. Overall, this work has demonstrated that hot-air-drying of persimmon slices is a promising approach to create a value-added product with at least one year of shelf-life.

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Microwave Drying of Pitaya (Hylocereus) Peel and the Effects Compared with Hot-Air and Freeze-drying

Transactions of the ASABE ◽

10.13031/trans.13193 ◽

2019 ◽

Vol 62 (4) ◽

pp. 919-928 ◽

Cited By ~ 1

Author(s):

Ying Ming Chew ◽

V. An-Erl King

Keyword(s):

Freeze Drying ◽

Arrhenius Equation ◽

Moisture Diffusivity ◽

Microwave Drying ◽

Effective Moisture Diffusivity ◽

Fick’S Law ◽

Fick's Law ◽

Hot Air ◽

Effective Moisture ◽

Dpph Scavenging

Abstract. Microwave drying (MD) of pitaya peel was performed at 75, 225, 375, 525, and 750 W. The drying effects on the effective moisture diffusivity (De), total polyphenol content (TPC), betalain content, DPPH scavenging ability, and rehydration abilities of pitaya peel were examined. The data were compared with hot-air drying (HD) at 100°C for 4 h and freeze-drying (FD) for 24 h. The results showed that the MD kinetics of pitaya peel fit Fick’s law and the Arrhenius equation with an activation energy (Ea) of 34.08 W g-1. The De values of MD, which ranged from 2.35E-07 m2 s-1 (at 75 W) to 5.56E-06 m2 s-1 (at 750 W), indicated that the effectiveness of MD was appreciably higher than that of HD (2.44E-08 m2 s-1) and FD (4.43E-09 m2 s-1). Although MD resulted in decreased betacyanin (9.31 mg L-1 extract) and betaxanthin (6.58 mg L-1 extract) contents, the DPPH inhibition of pitaya peel remained at 75% due to an increase in TPC (115 mg GAE per 100 FW). MD of pitaya peel can also provide higher rehydration ability than HD and was comparable to FD. This study concludes that MD of pitaya peel was highly effective while maintaining high levels of TPC and DPPH inhibition. Keywords: Arrhenius equation, Effective moisture diffusivity, Fick’s law, Microwave drying, Pitaya peel.

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Freeze-Drying of Sweet Peppers

The Journal of Agriculture of the University of Puerto Rico ◽

10.46429/jaupr.v54i1.11119 ◽

1969 ◽

Vol 54 (1) ◽

pp. 133-148

Author(s):

M. A. González ◽

E. Díaz Negrón ◽

H. Cancel ◽

A. C. Rivera

Keyword(s):

Shelf Life ◽

Freeze Drying ◽

Drying Rate ◽

Microbial Count ◽

Drying Time ◽

Hot Air ◽

Freeze Dried ◽

And Storage ◽

Index Of Quality ◽

Platen Temperature

Studies were conducted to dehydrate garden sweet peppers by means of hot-air and freeze-drying. Sweet peppers have tough, leathery skins which makes escape of moisture difficult and prolongs drying time. Our data indicates that dehydration of half-cut or slitted fruit is accomplished either by conventional hot-air or by freeze-drying in reasonably shorter periods of time than whole fruit. Change in color or shape was not observed in sweet peppers during freezedrying. Great deterioration in the green color was observed in the samples dehydrated with hot-air at 165° F. The shelf-life of the freeze-dried product is superior to that of the conventionally hot-air dried product. For freeze-drying the sweet peppers within a reasonable period of time, and to obtain a product with shape and color similar to the fresh fruit, a platen temperature of 180° F. should be used during 2 hours and then reduced to 150° F. during the rest of the drying period. Heat treatment to inactivate microbial activity of sweet peppers prior to freeze-drying greatly reduces the microbial count and does not affect the drying rate, quality and shelf-life of the end product. Deterioration of sweet peppers during drying and storage is characterized by development of off-flavor and color. Because the measurement of off-flavor is difficult in a mild pungent fruit such as sweet peppers, these studies indicate that measurement of changes in color can be used as an index of quality.

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Convective Drying of Fresh and Frozen Raspberries and Change of Their Physical and Nutritive Properties

Foods ◽

10.3390/foods8070251 ◽

2019 ◽

Vol 8 (7) ◽

pp. 251 ◽

Cited By ~ 7

Author(s):

Zoran Stamenković ◽

Ivan Pavkov ◽

Milivoj Radojčin ◽

Aleksandra Tepić Horecki ◽

Krstan Kešelj ◽

...

Keyword(s):

Ascorbic Acid ◽

Freeze Drying ◽

Color Change ◽

Quality Criteria ◽

Ascorbic Acid Content ◽

Biologically Active ◽

Convective Drying ◽

Total Phenolic ◽

Anthocyanin Content ◽

Freeze Dried

Raspberries are one of Serbia’s best-known and most widely exported fruits. Due to market fluctuation, producers are looking for ways to preserve this fresh product. Drying is a widely accepted method for preserving berries, as is the case with freeze-drying. Hence, the aim was to evaluate convective drying as an alternative to freeze-drying due to better accessibility, simplicity, and cost-effectiveness of Polana raspberries and compare it to a freeze-drying. Three factors were in experimental design: air temperature (60, 70, and 80 °C), air velocity (0,5 and 1,5 m · s−1), and state of a product (fresh and frozen). Success of drying was evaluated with several quality criteria: shrinkage (change of volume), color change, shape, content of L-ascorbic acid, total phenolic content, flavonoid content, anthocyanin content, and antioxidant activity. A considerable influence of convective drying on color changes was not observed, as ΔE was low for all samples. It was obvious that fresh raspberries had less physical changes than frozen ones. On average, convective drying reduced L–ascorbic acid content by 80.00–99.99%, but less than 60% for other biologically active compounds as compared to fresh raspberries. Convective dried Polana raspberry may be considered as a viable replacement for freeze-dried raspberries.

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Novel Ingredients Based on Grapefruit Freeze-Dried Formulations: Nutritional and Bioactive Value

Foods ◽

10.3390/foods8100506 ◽

2019 ◽

Vol 8 (10) ◽

pp. 506 ◽

Cited By ~ 2

Author(s):

Marta Igual ◽

Laura Cebadera ◽

Rosa Mᵃ Cámara ◽

Claudia Agudelo ◽

Nuria Martínez-Navarrete ◽

...

Keyword(s):

Molecular Weight ◽

Antioxidant Capacity ◽

High Molecular Weight ◽

Freeze Drying ◽

Natural Fibers ◽

Gum Arabic ◽

Bamboo Fiber ◽

Microwave Drying ◽

Food Ingredients ◽

Freeze Dried

Grapefruit is a fruit with interesting nutritional value and functional properties, but a short life. Freeze-drying (FD) is a valuable technique as it produces high-quality dehydrated products. This study is aimed to obtain new food ingredients based on freeze-dried grapefruit formulated with high molecular weight solutes (gum arabic and bamboo fiber) in three different proportions (F1, F2, and F3). To improve the FD, a mild microwave drying pre-treatment was applied. Influence of the water content and the presence of high molecular weight solutes on freeze-drying kinetics was tested by Midilli-Kucuk and Page models. The best FD kinetic model fit on grapefruit powders were Midilli-Kucuk for F2 and F3, and Page for F1, and the adequate freeze-drying times for F1, F2, and F3 were 24, 16, and 18 h, respectively. Final samples were evaluated for nutritional and antioxidant capacity. Gum arabic and bamboo fiber present a protector effect, which results in a significant antioxidant capacity due to the protection of flavonoids and antioxidant vitamins. These novel food ingredients could be of great interest for the food industry in order to develop foods with improved antioxidant capacity as well as enriched in natural fibers and/or micronutrients.

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