Effect of Freeze-drying and Oven-drying Methods on Flavonoids Content in two Romanian Grape Varieties

The aims of this work was to investigate the effect of thermal drying method (vacuum oven drying), and nonthermal drying method (freeze drying) on the flavonoids content in two red grape varieties (Cabernet Sauvignon and Merlot) from different grape components (seed, skin, and pulp) collected from two experimental fields, Bucium and Copou (North East of Romania). In general, the fresh skin of Cabernet and Merlot varieties has the highest flavonoids content followed by those obtained by oven-drying and freeze-drying process. A similar situation was observed in the other component of grape varieties like pulp and seeds meaning in the way that the flavonoid content in oven-dried samples were higher than that in the freeze-dried samples. In addition, from both varieties, Merlot collected from Bucium presented the highest content compared with Cabernet.

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Proximate Analysis of Goat Milk Yogurt Powder Produced by Freeze Drying and Vacuum-Oven Drying and in Comparing with Freeze-Dried Yogurt Powder Prepared with Tualang Honey

Journal Of Agrobiotechnology ◽

10.37231/jab.2021.12.1s.275 ◽

2021 ◽

Vol 12 (1S) ◽

pp. 101-111

Author(s):

Siti Norhannani Ahmat Azemi ◽

Norshafiqah Zainul ◽

Asmaliza Abd. Ghani ◽

John Tang Yew Huat

Keyword(s):

Moisture Content ◽

Protein Content ◽

Freeze Drying ◽

Ph Value ◽

Goat Milk ◽

Drying Method ◽

Vacuum Oven ◽

Oven Drying ◽

Freeze Dried ◽

Tualang Honey

This study was carried out to produce powdered yogurt from goat milk with longer shelf life.Two methods of drying process of yogurt were used which are vacuum-oven drying (VD) and freezedrying (FD). Goat milk yogurt powder prepared with added Tualang honey (TH) was produced by freeze-drying method. In this study, four formulations of yogurt were prepared with the addition of commercial yogurt containingas starter culture.Granulated sugar was added about 8% into the yogurt as control sample. While other three yogurts were prepared with 8% of Tualang honey, 6% of Tualang honey with 2% of sugar and 4% of Tualang honey with 4% of sugar. The proximateanalysis was used in order to identify the proximate composition and pH value of the yogurt. The moisture content of goat milk yogurt, VD goat yogurt powder and FD goat yogurt powder were 79.20%, 8.22% and 9.66% respectively. While, the moisture content for FD goat yogurt powder with addition of 4%, 6% and 8% Tualang honey were 15.12%,15.92% and 13.53% respectively.While the value of ash content for FD goat milk yogurt powder with addition of 4%, 6% and 8% Tualang honey were 0.37%, 0.35% and 0.50% respectively. The total protein content for goat milk yogurt was 4.61% whilein VD goat yogurt powder and FD goat yogurt powder were 15.04% and 15.07% respectively. The value of protein content for FD goat milk yogurt powder with addition of 8% of Tualang honey was 15.38%. The pH value ofgoat milk sample and fresh yogurt goat milk were 6.52 and 3.82. The pH values for fresh yogurt with addition of 4%, 6% and 8% of Tualang honey were 4.64, 4.68 and 4.73.Vacuum-oven drying method and freeze-drying method did not show any significant different in moisture, ash and protein content but showed significant different in pH value.

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Effects of drying methods on the physicochemical properties and antioxidant capacity of Kuini powder

BRAZILIAN JOURNAL OF FOOD TECHNOLOGY ◽

10.1590/1981-6723.08620 ◽

2021 ◽

Vol 24 ◽

Author(s):

Gan Wei Shuen ◽

Lew Yan Yi ◽

Thor Sing Ying ◽

Germaine Chng Yu Von ◽

Yus Aniza Binti Yusof ◽

...

Keyword(s):

Freeze Drying ◽

Colour Change ◽

Carotenoid Content ◽

Total Phenolic ◽

Drying Methods ◽

Vacuum Oven ◽

Oven Drying ◽

Convection Oven ◽

Total Carotenoid Content ◽

Freeze Dried

Abstract Kuini powders were obtained through spray-drying, freeze-drying, vacuum oven drying and convection oven drying. Colour, water activity (Aw), moisture content, hygroscopicity, wettability, flowability, degree of caking, water solubility index (WSI), total colour change, total phenolic content and total carotenoid content of Kuini powders were determined and compared. Convection oven drying resulted in the highest yield (46.97%), moisture content (4.91%), Aw (0.55) and WSI (74.33%) among all the drying methods. However, convection oven-dried Kuini powder had the lowest hygroscopicity and wettability, which were 18.66% and 12.04 s, respectively. Spray drying resulted in poor hygroscopicity (22.41%), degree of caking (22.16%), wettability (275s), WSI (45.67%) and higher colour change (59.81). Least total colour change (19.05) and higher yellowness (57.31) were observed in freeze-drying. In addition, freeze-dried Kuini powder had the highest total phenolic content (24.76 mg/100 g) and total carotenoid content (1.61 mg/100 g). Drying temperature had a negative and significant correlation with the retention of color pigments and antioxidant content. The physicochemical properties and antioxidant content of freeze-dried Kuini powder were preferred over spray-dried, vacuum oven-dried and convection oven-dried powders. Hence, freeze-drying offers potential application in the food products.

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Effect of Supplementation of Dried Bioflocs Produced by Freeze-Drying and Oven-Drying Methods on Water Quality, Growth Performance and Proximate Composition of Red Hybrid Tilapia

Journal of Marine Science and Engineering ◽

10.3390/jmse10010061 ◽

2022 ◽

Vol 10 (1) ◽

pp. 61

Author(s):

Tarq Binalshikh-Abubkr ◽

Marlia Mohd Hanafiah

Keyword(s):

Water Quality ◽

Body Composition ◽

Growth Performance ◽

Freeze Drying ◽

Energy Levels ◽

Fish Growth ◽

Drying Methods ◽

Oven Drying ◽

Freeze Dried

Supplementation of dried bioflocs for red hybrid tilapia (Oreochromis sp.) was examined during 57 days of feeding trials. Five experimental treatments; T1 (the control; without bioflocs), T2 (4% freeze-dried bioflocs), T3 (16% freeze-dried bioflocs), T4 (4% oven-dried bioflocs), and T5 (16% oven-dried bioflocs) were prepared to examine the water quality, growth performance and body composition of red hybrid tilapia. T2 and T4 treatments resulted in a higher growth rate and survival similar to the control, while T3 and T5 treatments showed the lowest values of growth performance among all treatments. T1 treatment showed the best quality of culture water followed by T2 and T4 treatments, while T3 treatment resulted in poor water quality followed by T5 treatment. Based on these results, the ratios of bioflocs (4% and 16%) had more effect on fish growth and water quality than the drying methods (freeze-drying and oven-drying). The ratio of 4% freeze-dried or oven-dried bioflocs provided higher growth rates and better water quality parameters similar to the control, while the ratio of 16% showed the worst growth performance and water quality in the present study. In addition, body compositions of tilapia fed 4% dried bioflocs showed better nutritional value than tilapia fed 16% dried bioflocs. Protein and energy levels showed an increasing trend with decreasing supplement levels of bioflocs. Moisture content was significantly higher when supplementation of 16% bioflocs was used. Overall, supplementation of 4% freeze-dried or oven-dried bioflocs can be successively included in red hybrid tilapia diets without any effects on growth or body composition and can result in a good quality of culture water for red hybrid tilapia.

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Effect of Freeze, Oven and Microwave Pretreated Oven Drying on Color, Browning Index, Phenolic Compounds and Antioxidant Activity of Hawthorn (Crataegus orientalis) Fruit

Notulae Botanicae Horti Agrobotanici Cluj-Napoca ◽

10.15835/nbha46211027 ◽

2018 ◽

Vol 46 (2) ◽

pp. 449-456 ◽

Cited By ~ 11

Author(s):

Hacer COKLAR ◽

Mehmet AKBULUT ◽

Semih KILINC ◽

Ali YILDIRIM ◽

Iliasu ALHASSAN

Keyword(s):

Antioxidant Activity ◽

Phenolic Compounds ◽

Total Phenolic Content ◽

Phenolic Content ◽

Total Phenolic ◽

Drying Methods ◽

Drying Method ◽

Microwave Pretreatment ◽

Oven Drying ◽

Freeze Dried

Flowers, leaves and fruits of hawthorn plant are traditionally used for treating diseases like hypertension and atherosclerosis. The medicinal effects of the plant are generally attributed to its phenolic compounds. However, the fruits are perishable materials because of their high content of water, and generally dried and stored to be used outside its season. The main aim of this research was to investigate the effect of different drying methods on phenolic compounds of the hawthorn fruit. Fruits were collected from the wild growing trees in Turkey. De-seeded fruits were dried in freeze-, oven- (60 oC) and microwave pretreated oven drying (microwave application for 5 min at 360 W before drying at 60 oC) methods and analyzed for antioxidant activity, phenolic compounds, total phenolic content and color parameters. Total phenolic content of fresh hawthorn fruits was found as 13.36 mg g-1 DW. Oven- and microwave pretreated oven drying methods had a reductive effect on total phenolic content and antioxidant activity of fruits when compared to freeze drying method. (-)-Epicatechin (994.10 mg kg-1 DW), rutin (765.30 mg kg-1 DW), and procyanidin B2 (553.80 mg kg-1 DW) were the main phenolics of the fruit. Lowest values of these three compounds were observed in oven-dried fruits. Microwave pretreatment oven drying method resulted in browner product. Although the highest phenolic concentration and antioxidant activity were occurred in freeze-dried sample, microwave pretreatment before oven drying could be applied to reduce the time and cost of drying in terms of phenolic compounds and antioxidant activity.

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The Influence of Different Drying Methods on Constituents and Antioxidant Activity of Saffron from China

International Journal of Analytical Chemistry ◽

10.1155/2015/953164 ◽

2015 ◽

Vol 2015 ◽

pp. 1-8 ◽

Cited By ~ 18

Author(s):

Yingpeng Tong ◽

Xingyi Zhu ◽

Yongqiu Yan ◽

Ruoxi Liu ◽

Feng Gong ◽

...

Keyword(s):

Antioxidant Activity ◽

Microwave Drying ◽

Drying Methods ◽

Drying Method ◽

Vacuum Oven ◽

Oven Drying ◽

Electric Oven ◽

Long Time ◽

Spectrum Effect

More and more saffron has been cultivated in China because of the increasing saffron demand, but no paper has studied the influence of drying methods on the quality of Chinese saffron. In this paper, three different dehydration treatments applied in actual production were evaluated: dehydration with electric oven, vacuum oven, and microwave. We determined that the highest quality of saffron will be obtained when fresh saffron is treated at higher temperatures (no more than 70°C) for a long time by electric oven drying and vacuum oven drying. In microwave drying, treatments at lower microwave power and longer time benefit the quality of saffron. In addition, the influence of the drying method on antioxidants in saffron is discussed. The correlation between individual saffron profiles and the antioxidant value was estimated by spectrum-effect relationships analysis.

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Proximate Chemical Composition of Dried Shrimp and Tilapia Waste Bioflocs Produced by Two Drying Methods

Journal of Marine Science and Engineering ◽

10.3390/jmse9020193 ◽

2021 ◽

Vol 9 (2) ◽

pp. 193

Author(s):

Tarq Binalshikh-Abubkr ◽

Marlia M. Hanafiah ◽

Simon Kumar Das

Keyword(s):

Chemical Composition ◽

Freeze Drying ◽

Drying Methods ◽

Shrimp Waste ◽

Drying Method ◽

Iron Copper ◽

Nutrient Value ◽

Nitrogen Free Extract ◽

Freeze Dried ◽

Proximate Chemical Composition

The effects of two waste sources, red hybrid tilapia (Oreochromis sp.) and whiteleg shrimp (Litopenaeus vannamei), and two drying methods (freeze-drying and oven-drying) on the proximate chemical composition of bioflocs were investigated. In total, four kinds of experimentally treated bioflocs were compared to identify the best waste source and drying method to produce biofloc of an acceptable nutrient value: freeze-dried shrimp biofloc (FDSBF), oven-dried shrimp biofloc (ODSBF), freeze-dried tilapia biofloc (FDTBF), and oven-dried tilapia biofloc (ODTBF). The protein, lipid, ash, fiber, total nitrogen free extract (NFE), and energy contents of the dried bioflocs ranged from 12.12 to 24.09 g/100 g, 0.35 to 0.92 g/100 g, 42.45 to 61.01 g/100 g, 7.43 to 17.11 g/100 g, 16.45 to 18.59 g/100 g, and 0.99 to 1.94 Kcal g−1, respectively. Statistically, there were significant differences within the means of the two biofloc sources in terms of their proximate compositions (p < 0.05). The average values between the drying methods for protein, lipid, total NFE, and energy were also significantly different, while no significant differences (p > 0.05) were recorded for ash and fiber. Amino acids (AAs) were higher in FDTBF, followed by ODTBF. The mineral profiles showed that phosphorous, potassium, manganese, selenium, and copper were higher in the tilapia waste bioflocs, while calcium, zinc, iron, copper, chromium, and cobalt were higher in the shrimp waste bioflocs. Although the statistical analysis showed that the shrimp waste bioflocs had higher levels of lipid, fiber, total NFE, and minerals, the tilapia waste bioflocs contained higher levels of potential AAs, energy, and protein, which are regarded as expensive ingredients in aquaculture feeding. This study indicates that biofloc derived from tilapia waste can be regarded as a more suitable source of biofloc meal (in terms of protein, ash, energy, and AAs) than biofloc derived from shrimp waste. Our findings also suggest that freeze-drying is a more effective drying method for drying biofloc, as it efficiently maintains nutritional quality.

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The Effect of Drying Methods on Water-Soluble Carbohydrates and Crude Protein Concentrations and Their Ratio in Two Perennial Ryegrass Cultivars

Agronomy ◽

10.3390/agronomy9070383 ◽

2019 ◽

Vol 9 (7) ◽

pp. 383 ◽

Cited By ~ 2

Author(s):

Cristian J. Moscoso ◽

Sarah A. Morgan ◽

M. Jordana Rivero

Keyword(s):

Perennial Ryegrass ◽

Crude Protein ◽

Freeze Drying ◽

Joint Effect ◽

Water Soluble ◽

Soluble Carbohydrates ◽

Drying Methods ◽

Drying Method ◽

Freeze Dried ◽

Water Soluble Carbohydrates

The objective of this study was to assess the joint effect of perennial ryegrass cultivars and drying methods on concentrations of water-soluble carbohydrates (WSC) and crude protein (CP) and WSC/CP ratio. AberMagic AR1 and Expo AR1 forage were collected in December 2016, March, June, September and November 2017 and either oven-dried at 60 °C for 48 h (OD_60), at 80 °C for 16 h (OD_80), frozen at −80 °C for 48 h then freeze-dried (−80_FD), or flash-frozen with liquid N then freeze-dried (LN_FD). Data were analyzed by ANOVA in a factorial design with cultivar and drying method as factors. AberMagic AR1 had between 9.0 to 31.5% higher WSC concentration than Expo AR1 in the four samplings. Freeze-drying preserved more WSC than oven-drying treatments (+22.7%), particularly in June. The CP concentration of Expo AR1 was higher only in December (+6.8%), and was 22.9 and 10.9% higher in OD_60 samples compared to LN_FD samples in December and November, respectively. The WSC/CP ratio varied in June, being greater in AberMagic AR1 (+36.1%). Drying method affected WSC/CP ratio in December, June and November where freeze-drying produced greater ratios. Drying techniques generated differences in WSC, CP and WSC/CP ratio, which may affect the accuracy of the estimated impacts of forages on productivity and N use efficiency.

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The Effect of Different Drying Methods on Primary and Secondary Metabolites in Korean Mint Flower

Agronomy ◽

10.3390/agronomy11040698 ◽

2021 ◽

Vol 11 (4) ◽

pp. 698

Author(s):

Chang Ha Park ◽

Hyeon Ji Yeo ◽

Chanung Park ◽

Yong Suk Chung ◽

Sang Un Park

Keyword(s):

Amino Acids ◽

Secondary Metabolites ◽

High Performance ◽

Freeze Drying ◽

Sinapic Acid ◽

Drying Methods ◽

Oven Drying ◽

Primary And Secondary Metabolites ◽

Freeze Dried ◽

Β Carotene

Edible flowers have been used in the food and beverage industries because of their high nutritional value, flavor, and scent. For the storage of edible flowers used in these industries, drying is a necessity to store the materials more easily and prevent the damage of metabolites in the flowers. However, drying may affect metabolite retention because drying conditions can differ according to the various methods. In this study, Agastache rugosa flowers were dried using four different methods (oven drying at 25 ± 1 °C, 50 ± 1 °C, 80 ± 1 °C, and freeze drying) and primary and secondary metabolites were analyzed using high-performance liquid chromatography (HPLC) and gas chromatography time-of-flight mass spectrometry (GC-TOF/MS). Freeze-dried flower samples contained higher levels of carotenoids (lutein, 13Z-β-carotene, β-carotene, and 9Z-β-carotene) and phenolics (rosmarinic acid, ferulic acid, and sinapic acid). Contrarily, the 80 °C oven-dried flower samples contained higher levels of most amino acids and flavonoids (including acacetin and tilianin) and at 25 °C and 50 °C contained higher levels of carbohydrates. Therefore, freeze-drying is a suitable method for retaining carotenoids and phenolics. In contrast, oven drying at 50 °C was highly recommended to retain amino acids and flavonoids.

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Changes in Physicochemical Properties and Volatile Compounds of Roselle (Hibiscus sabdariffa L.) Calyx during Different Drying Methods

Molecules ◽

10.3390/molecules26206260 ◽

2021 ◽

Vol 26 (20) ◽

pp. 6260

Author(s):

Nurul Hanisah Juhari ◽

Helle Jakobe Martens ◽

Mikael Agerlin Petersen

Keyword(s):

Moisture Content ◽

Physicochemical Properties ◽

Volatile Compounds ◽

Freeze Drying ◽

Cell Structure ◽

Vacuum Drying ◽

Drying Methods ◽

Oven Drying ◽

Sun Drying ◽

Freeze Dried

Fresh roselle are high in moisture and deteriorate easily, which makes drying important for extending shelf-life and increasing availability. This study investigated the influence of different drying methods (oven-drying, freeze-drying, vacuum-drying, and sun-drying) on the quality of roselle calyx expressed as physicochemical properties (moisture content, water activity, soluble solids, color), volatile compounds, and microstructure. Oven-drying and freeze-drying reduced moisture content most while vacuum-drying and sun-drying were not as efficient. All drying methods except sun-drying resulted in water activities low enough to ensure safety and quality. Vacuum-drying had no impact on color of the dry calyx and only small impact on color of water extract of calyx. Drying reduced terpenes, aldehydes, and esters but increased furans. This is expected to reduce fruity, floral, spicy, and green odors and increase caramel-like aroma. Sun-drying produced more ketones, alcohols, and esters. Scanning electron microscopy revealed that freeze-drying preserved the cell structure better, and freeze-dried samples resembled fresh samples most compared to other drying techniques. The study concludes that freeze-drying should be considered as a suitable drying method, especially with respect to preservation of structure.

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Effect of different drying methods on quality attributes of beetroot (Beta vulgaris) slices

World Journal of Science Technology and Sustainable Development ◽

10.1108/wjstsd-11-2017-0043 ◽

2018 ◽

Vol 15 (3) ◽

pp. 287-298 ◽

Cited By ~ 4

Author(s):

Manhal Gobara Hamid ◽

Abdel Azim Ahmed Mohamed Nour

Keyword(s):

Chemical Composition ◽

Beta Vulgaris ◽

Quality Attributes ◽

Rich Source ◽

Total Phenolic ◽

Drying Methods ◽

Drying Method ◽

Content Type ◽

Oven Drying ◽

Freeze Dried

PurposeThe purpose of this paper is to evaluate the effect of different drying methods on quality attributes of beetroot slices.Design/methodology/approachThree drying methods (sun, oven and freeze-drying) were applied to dry fresh slices of beetroot cultivar (Beta vulgaris). The chemical composition, minerals, nitrate, betalains, total phenolic, total flavonoid and color were measured for fresh and dried slices.FindingsThe chemical composition, minerals, nitrate, bioactive compounds and color were measured for fresh and dried slices. Regardless of the drying method, the results showed that the chemical composition, total energy, minerals and nitrate of the dried slices were significantly (p=0.05) increased compared to that of fresh slices. Sun and oven drying of the slices significantly (p=0.05) reduced total betalain and betacynin. However, betaxanthin was significantly (p=0.05) increased. Total phenolics content of fresh beetroot was significantly (p=0.05) increased after sun and oven drying but total flavonoids were decreased. The 2,2,-diphenyl-2-picryl-hydrazyl (DPPH) of fresh beetroot was increased significantly (p=0.05) after sun and oven drying. The measurement of the color of the powder showed that there is a decrease in lightness (L) depending on the drying method applied. A maximum reduction in lightness was observed in powder of sun-dried slices. The color of the powder obtained from freeze-dried slices was stable compared to other drying methods.Practical implicationsBeetroot is a rich source of nutrients but with short shelf life. Dried beetroot has more keeping quality than the fresh one.Originality/valueThe study uses beetroot as a rich source of nutrients as well as natural antioxidant source. Betalain compounds are preserved in beetroot and a high source of phenolics and flavonoids. Flavonoids are a group of phenolic products of plant metabolism with high antioxidant properties to protect against diseases without side effects.

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