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

2018 ◽  
Vol 15 (3) ◽  
pp. 287-298 ◽  
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.

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

2018 ◽  
Vol 46 (2) ◽  
pp. 449-456 ◽  
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.

Effect of drying methods on the nutritional content and In- vitro Antioxidant capacity of Chenopodium album L. and Spinacia oleracea L.

2021 ◽  
pp. 4361-4366
Author(s):  
Sonia Singh ◽  
Neetu Agrawal
Keyword(s):  
Spinacia Oleracea ◽  
Chenopodium Album ◽  
Microwave Drying ◽  
Total Phenolic ◽  
Drying Methods ◽  
Drying Method ◽  
Nutrient Quality ◽  
Oven Drying ◽  
Sun Drying ◽  
Hot Air

The herbs, Chenopodium album Linn. and Spinacia oleracea Linn. belongs to Chenopodiaceae family, are the two nutritious and edible green leafy food crops, abundantly found especially in the northern-west region of India. These plants have gained renown popularity, because of their high nutritional content including protein, amino acids, carbohydrate, and even the presence of phenolic components, which ultimately may get affected with drying and storage techniques. Impact of different drying methods (microwave drying at 4 minutes, hot air oven drying at 5 hours and sun drying at 8-10 hours) on nutrient quality and antioxidant property of Chenopodium album Linn. and Spinacia oleracea Linn. leaves were evaluated by using UV spectrophotometritc assay, total phenolic content and DPPH free radical scavenger method. Drying treatments were significantly decreased the moisture, carbohydrate and protein content present in C.album and S. oleracea. Hot air oven drying method produced dried samples of C.album and S. oleracea had significantly similar antioxidant activity when compared with the samples obtained from sun drying method. The dried samples obtained from hot air oven drying technique showed significant presence of total phenolic content in C. album and S. oleracea (6.44±0.12 mg/g, 6.69±0.40 mg/g) whilst the traditional sun drying method produced 8.00±0.02 mg/g and 7.89±0.37 mg/g). It is concluded that microwave drying and hot air oven drying were the methods to preserve appreciable percentage of nutrient components compared to the fresh samples. On other hand, the traditional method produced substantial reduction of nutrient quality. From statistical analysis, hot air oven drying technique was considered as optimum method which showed satisfactory % retention of protein (65.86%) and carbohydrate (85.95%) at 5 hours (shorter time than sun drying time period) along with significant antioxidant activity (34.89 μg/mL and 35.60 μg/mL) similar as obtained from the traditional technique (32.00 μg/mL).

scholarly journals Pengaruh Dua Metode Pengeringan Pada Aktivitas Antibakteri Ashitaba (Angelica keiskei ) Terhadap Streptococcus mutans

2018 ◽  
Vol 4 (1) ◽  
pp. 18-25
Author(s):  
Dyke Gita Wirasisya ◽  
Yohanes Juliantoni ◽  
Wahida Hajrin
Keyword(s):  
Antibacterial Activity ◽  
Streptococcus Mutans ◽  
Total Phenolic Content ◽  
Phenolic Content ◽  
Total Phenolic ◽  
Drying Methods ◽  
Drying Method ◽  
Oven Drying ◽  
Sun Drying ◽  
Angelica Keiskei

The aim of this study was to determine a change that occurs in total phenolic content (TPC) and antibacterial activity of ashitaba (Angelica keiskei) after dried using two different methods : sun and oven drying. The effectiveness of the drying methods was evaluated in term of total phenolic content (TPC) by using spectrophotometric assay with Folin-Ciocalteu reagent and antibacterial activity againts Streptococcus mutans by in vitro macrodilution assay. Oven drying at 60oC possessed high TPC (2,98 ± 0,0935 g EAG/100g) compared to sun drying method (1,72 ± 0,0142 g EAG/100g). Simillar pattern was also observed in antibacterial activity. Oven drying have higher antibacterial activity with the MBC (minimal bactericidal concentration) value of 0,5 mg/mL againts Streptococcus mutans. Therefore, sun drying is not suggested for drying method of ashitaba in terms of total phenolic content and antibacterial activity compared with oven drying methods.

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

2019 ◽  
Vol 70 (2) ◽  
pp. 491-494
Author(s):  
Lacramioara Oprica ◽  
Radu Gheorghe Antohe ◽  
Andreea Verdes ◽  
Marius Nicusor Grigore
Keyword(s):  
Freeze Drying ◽  
Drying Methods ◽  
Drying Method ◽  
Vacuum Oven ◽  
Oven Drying ◽  
North East ◽  
Freeze Dried ◽  
Red Grape ◽  
Grape Varieties ◽  
Fresh Skin

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.

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

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.

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

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.

scholarly journals The Influence of Drying Methods on the Chemical Composition and Body Color of Yellow Mealworm (Tenebrio molitor L.)

Insects ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 333
Author(s):  
Letlhogonolo Selaledi ◽  
Monnye Mabelebele
Keyword(s):  
Fatty Acids ◽  
Chemical Composition ◽  
Small Scale ◽  
Drying Methods ◽  
The Sun ◽  
Body Color ◽  
Yellow Mealworm ◽  
Oven Drying ◽  
Insect Rearing ◽  
Freeze Dried

To preserve the quality of the yellow mealworm, different drying methods are being explored by farmers and processors. However, the energy costs associated with these methods are usually high for smallholder insect-rearing farmers. Thus, the core aim of this study was to investigate different drying procedures and their impact on the chemical composition of yellow mealworm larvae. Yellow mealworms (exposed to sun, oven and freeze drying) were later analyzed for their chemical composition and body color. Crude protein (CP) content of freeze and oven-dried mealworms were similar (p > 0.05), but higher (p < 0.05) than those of the sun-dried samples. The b (yellowness) color of the sun-dried samples scored the lowest value (p < 0.05) in comparison with both oven and freeze-dried samples. The majority of the essential amino acids were higher (p < 0.05) in the sun-dried mealworms than both oven and freeze-dried samples. Similarly, the fat content of sun-dried mealworms was higher (p < 0.05) than if they had been oven or freeze dried. However, SFA (saturated fatty acids), PUFA (polyunsaturated fatty acids) and n-6 fatty acids were similar (p > 0.05) for all drying methods. We, therefore, conclude that sun drying resulted in the same nutritional composition as freeze and oven drying despite the noted color changes. Freeze and oven-drying strategies can be used to formulate mealworm-based feed and food products without noticeable nutritional changes. For the benefit of small-scale insect-rearing farmers, an appropriate drying technology that is affordable and easy to use should be developed considering the needs and experiences of these farmers.

Color, microstructure, physicochemical, textural and sensory properties with the retention of secondary metabolites in convective-, microwave- and freeze-dried carrot (Daucus carota) slices

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Gulcin Yildiz
Keyword(s):  
Secondary Metabolites ◽  
Freeze Drying ◽  
Quality Characteristics ◽  
Sensory Properties ◽  
Convective Drying ◽  
Total Phenolic ◽  
Drying Methods ◽  
Content Type ◽  
Freeze Dried ◽  
The Impact

Purpose This work was undertaken to evaluate the impact of different drying methods (convective, microwave and freeze drying) on color, selected secondary metabolites (total phenolic substances, ascorbic acid, beta-carotene and antioxidant capacity), texture (hardness), sensory properties and microstructure of carrot slices.Design/methodology/approachConvective drying at three different temperatures (55, 65 and 75 °C), microwave drying at two different power levels (100 and 200 W) and freeze drying were applied.FindingsSignificant differences were found among fresh and dried-carrot slices. Convective-dried carrots showed better quality characteristics in comparison with microwave-dried carrots. The convective-dried carrots at 65 °C exhibited the highest retention of bioactive compounds and best color among all convective drying conditions. The microwave-dried carrot slices at lower power (100 W) showed higher quality characteristics compared to the dried carrots at 200 W. The freeze-dried carrots exhibited the highest retention of secondary metabolites, sensory properties and best color among all drying methods.Originality/value The results from this study are significant for the processing of dried carrots by optimizing the conditions to obtain a high-quality product. Overall, freeze drying is a promising application as shown in the present study by its capability to better retention carrot quality underlying color, sensory, texture, microstructure and secondary metabolites.

scholarly journals Influence of Freezing and Different Drying Methods on Volatile Profiles of Strawberry and Analysis of Volatile Compounds of Strawberry Commercial Jams

Molecules ◽  
2021 ◽  
Vol 26 (14) ◽  
pp. 4153
Author(s):  
Doaa Abouelenein ◽  
Ahmed M. Mustafa ◽  
Simone Angeloni ◽  
Germana Borsetta ◽  
Sauro Vittori ◽  
...  
Keyword(s):  
Microwave Drying ◽  
Drying Methods ◽  
Volatile Profile ◽  
Drying Method ◽  
Drying Process ◽  
Total Volatile ◽  
Ethyl Hexanoate ◽  
Complete Destruction ◽  
Freeze Dried ◽  
Volatile Profiles

Strawberry is the most consumed berry fruit worldwide due to its unique aroma and flavor. Drying fruits to produce a powder represents one of the possible conservation methods to extend their shelf-life. The aim of the present study was to compare the influence of freezing and different drying methods on the volatile profile of strawberry using the HS-SPME/GC–MS method, in addition to analysis of strawberry jam volatiles. A total of 165 compounds were identified, accounting for 85.03–96.88% of the total volatile compositions. Results and PCA showed that freezing and each drying process affected the volatile profile in a different way, and the most remarkable representative differential volatiles were ethyl hexanoate, hexyl acetate, (E)-2-hexenyl acetate, mesifurane, (E)-nerolidol, γ-decalactone, 1-hexanol, and acetoin. Shade air-dried, frozen, freeze-dried, and oven-dried 45 °C samples retained more of the fruity and sweet aromas of strawberry, representing more than 68% of the total aroma intensity according to the literature. In contrast, the microwave-drying method showed drastic loss of fruity esters. Strawberry jams demonstrated complete destruction of esters and alcohols in most jams, while terpenes were significantly increased. These findings help better understand the aroma of strawberry and provide a guide for the effects of drying, freezing, and jam processing.

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