scholarly journals Proximate Composition, Antinutrient Content and Functional Properties of Soursop Flour as Influenced by Oven and Freeze Drying Methods

2014 ◽  
Vol 2 (2) ◽  
pp. 106-110 ◽  
Author(s):  
Terhemba Iombor ◽  
Innocentia Olaitan ◽  
Rhoda Ede

The effect of Oven and freeze drying methods on the proximate composition, anti-nutrient and selected physical attributes of soursop flours were determined using standard methods. The fruit pulp was frozen at -30 and freeze dried at -40 for 72hrs while oven drying was performed at 70 for 48hrs. Oven drying significantly (p≤0.05) lowered the fat (7.30±0.23%), moisture (12.40±0.29%) and carbohydrate (40.70±0.12%) content of soursop flour while freeze drying significantly (p≤0.05) lowered the protein (18.72±0.10%), fibre (12.30±0.23%), ash (6.30±0.17%) and energy (212.704±0.10%) content of the flour. The oven dried flour had higher phytate (0.03±0.10%) and oxalate (0.03±0.00%) content while the freeze dried flour had higher tannin (0.52±0.00%) content. The physical attributes of the flours however revealed that the freeze dried flour significantly (p≤0.05) had higher values for viscosity (32.50±0.29%), water absorption capacity (57.30±0.17%), swelling index (50.10±0.06%), solubility (22.30±0.17%), oil absorption capacity (24.60±0.23%) and emulsion capacity (24.60±0.23%) while the oven dried flour had higher values for bulk density (421.20±0.12%) and foam capacity (25.30±0.17%). Freeze dried soursop flour had better physical attributes, lower nutrient and anti-nutrient content.

2022 ◽  
Vol 10 (1) ◽  
pp. 61
Author(s):  
Tarq Binalshikh-Abubkr ◽  
Marlia Mohd Hanafiah

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.


2019 ◽  
Vol 70 (2) ◽  
pp. 491-494
Author(s):  
Lacramioara Oprica ◽  
Radu Gheorghe Antohe ◽  
Andreea Verdes ◽  
Marius Nicusor Grigore

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.


2021 ◽  
Vol 24 ◽  
Author(s):  
Gan Wei Shuen ◽  
Lew Yan Yi ◽  
Thor Sing Ying ◽  
Germaine Chng Yu Von ◽  
Yus Aniza Binti Yusof ◽  
...  

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.


Agronomy ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 698
Author(s):  
Chang Ha Park ◽  
Hyeon Ji Yeo ◽  
Chanung Park ◽  
Yong Suk Chung ◽  
Sang Un Park

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.


Molecules ◽  
2021 ◽  
Vol 26 (20) ◽  
pp. 6260
Author(s):  
Nurul Hanisah Juhari ◽  
Helle Jakobe Martens ◽  
Mikael Agerlin Petersen

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.


2017 ◽  
Vol 21 (1) ◽  
pp. 41-50 ◽  
Author(s):  
Mawardii Yusufe ◽  
Ali Mohammed ◽  
Neela Satheesh

Abstract The objective of the present study was to standardise the duration and temperatures of the conventional oven drying methods for best physical and sensory characteristics of dried tomato. The experiment consisted of two factor factorial design (3*2) with three levels of drying temperature (70°C, 80°C and 90°C) and two levels of drying duration (7 and 8 hours) with three replications. An improved and high yielding variety (Cochoro) of tomato released in 2007 for processing and widely grown in Ziwai (Maki), Ethiopia was used. Prior to drying, individual tomato fruits were washed and sliced into uniform thickness (8mm); then, the slices were placed on to the drying trays in a single layer to facilitate uniform drying in hot air oven set at predetermined temperatures per the respective treatments. Data were collected on different physical and sensory attributes and analysed using SAS software (version 9.2). The results showed that titratable acidity, total soluble solids and water absorption capacity were significantly (p≤0.001) increased due to the interaction of degree of temperature and duration of oven drying. In contrast, pH and water activity decreased as the drying temperature and duration increased. Drying at 70°C for 7 hours produced dried tomatoes with the highest sensorial acceptability and physical attributes while higher temperatures (80, 90°C) and longer duration (9 hours) significantly detract the quality of dried tomato. Hence, it is possible to add value and preserve tomatoes through oven drying at the right temperature and optimum duration.


2020 ◽  
Vol 16 (9) ◽  
Author(s):  
Halil İbrahim Odabaş ◽  
Ilkay Koca

AbstractRosa pimpinellifolia L. fruits (RPF) are promising source of anthocyanin pigments. The objectives of this study were to optimization of the aqueous two-phase extraction (ATPE) process of anthocyanin from RPF and microencapsulation of anthocyanin-rich RPF extract. The optimal ATPE conditions were as follows: 0% HCl, 30% ethanol, 19% ammonium sulfate, and liquid to solid ratio 51.71, 97.71 min, and 30°C extraction temperature. Predicted anthocyanin yield at the optimum conditions was 1578.90 mg cyanidin 3-glucoside equivalent/100 g dry fruit. ATPE resulting in 1.80-fold increase in the purity of anthocyanins when compared to conventional solvent extraction (CSE). The composition of the anthocyanins were determined with HPLC-QTOF-MS. Freeze-drying and spray-drying methods were employed for the production of microencapsulated anthocyanin pigments. The half times of microencapsulated anthocyanins at 4, 25 and 37°C were determined as 12.16, 6.60 and 3.12 months for freeze-dried microcapsules, and 16.50, 9.24 and 4.29 months for spray-dried microcapsules, respectively.


2018 ◽  
Vol 14 (2) ◽  
Author(s):  
Jun Yu ◽  
Zijian Shangguan ◽  
Xingju Yang ◽  
Dan Sun ◽  
Baoqing Zhu ◽  
...  

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.


2020 ◽  
Vol 2020 ◽  
pp. 1-5
Author(s):  
Matthew A. Achaglinkame ◽  
Eric Owusu-Mensah ◽  
Abena A. Boakye ◽  
Ibok Oduro

Snails, a delicacy in most tropical communities, are highly perishable and seasonal. Employed preservative methods are highly temperature dependent, adversely affecting their nutritional value and sensory properties. This study was aimed at determining the effect of size and drying time on the rehydration and sensory properties of freeze-dried snails. Snails were sized into three categories with average weights: 7.59 g (quarter-sized), 14.41 g (half-sized), and 30.71 g (whole), and freeze-dried for 15, 20, and 25 h. The moisture content and percent rehydration of the dried samples were determined by standard methods and sensory properties assessed by an in-house panel of 30 using a 5-point hedonic scale. The moisture content of the fresh and freeze-dried samples ranged from 65.80 to 75.20% and 3.25 to 10.24%, respectively. Freeze-dried samples had higher percent rehydration (27 to 102%) than the control; smoked snails (21 to 32%). Size had a significant (P<0.05) effect on the rehydration ability of the samples with the half-sized and freeze-dried for 15 h samples having the highest. The freeze-dried samples generally had higher consumer preference than the control in all attributes assessed. The findings show that freeze-drying snails (approximate weight of 14.4 g) for 15 h could be a consumer-preferred alternative preservative method for extending the shelf life of snails.


2018 ◽  
Vol 46 (2) ◽  
pp. 449-456 ◽  
Author(s):  
Hacer COKLAR ◽  
Mehmet AKBULUT ◽  
Semih KILINC ◽  
Ali YILDIRIM ◽  
Iliasu ALHASSAN

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.


Sign in / Sign up

Export Citation Format

Share Document