scholarly journals The effect of storage on some chemical and microbial properties of apricots dried with a combined solar energy assisted air and hot air assisted radio frequency drying system

2021 ◽  
Vol 7 (4) ◽  
pp. 259-271
Author(s):  
Hatice Neval Özbek ◽  
Aysel Elik ◽  
Melis Sever ◽  
Şakire Ecem Bulut ◽  
Derya Koçak Yanık ◽  
...  

Innovative combined solar energy assisted air and hot air assisted radio frequency drying system was used to dry unsulphured, sulphured (1 kg/ton and 2 kg/ton sulphur) and pistachio hull extract treated apricots. Unsulphured and sulphured apricots dried under sun were used as the control samples. The effects of different storage temperatures (5, 20 and 35oC) on residual sulphur content, β-carotene and microbial stability characteristics of dried apricots were studied. Also, the effect of storage temperature on the total phenolic content of dried apricots pre-treated with pistachio hull extract was investigated. The obtained results showed that the loss of sulphur and β-carotene was less in the products stored at 5oC compared to the products stored at 20 and 35oC. Sulphur treatment significantly inhibited the loss of β-carotene during storage. The maximum decrease in phenolic content of dried apricots pretreated with extract, was observed in samples stored at 20°C. In addition, extract treatment provided an advantage in terms of storage considering the microbial quality. The combined drying system caused less sulfur loss compared to sun drying.

2021 ◽  
Author(s):  
F. Kaabour ◽  
S. Mezaache-Aichour ◽  
K. Aissat

In this study, Daphne gnidium leaves extracts were screened for their Phenolic content, antimicrobial, antioxidant and antihemolitic activities. Decoction and maceration were used to obtain the aqueous (Aq E) and the ethanolic extract (Et E), respectively. Total phenolic content was determined using Folin–Ciocalteu reagent. Moreover, a disc diffusion assay and inhibition of mycelial growth test were applied to evaluate the antibacterial and antifungal activity. The extracts were also tested for their antioxidant effects in terms of DPPH, OH, H2O2, β-carotene, and ferrous ion chelating assays. To investigate antihemolytic activity, the 2,2,-azobis (2-amidinopropane) dihydrochloride (AAPH) was used to induce erythrocyte oxidative hemolysis. Results indicated that ethanolic extract (Et E) contains the highest polyphenol content (775.25 μg GAE/mg extract). The Et E inhibited the growth of bacterial strains with inhibition zone diameters from 7 to 15 mm. In contrast, no activities have been found against all fungal strains. In antihemolytic test, aqueous and ethanolic extracts showed almost the same effect with an HT50 value of 106 min. Ethanolic extract was found to be more active in DPPH and β-carotene assays (IC50: 5.76 μg/ml and 70% inhibition respectively). However, the aqueous extract showed a greater effect than the ethanolic one in metal chelating activity assay (IC50: 170 μg/ml), OH scavenging effect assay (IC50: 9.67 μg/ml) and H2O2 scavenging assay (IC50: 133.2 μg/ml).


Agriculture ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 183 ◽  
Author(s):  
Forough Khajehei ◽  
Jens Hartung ◽  
Simone Graeff-Hönninger

Recent studies have associated the consumption of yacon root as a functional plant food with reduced glycemic index and, due to its considerable phenolic acid levels, a protection of cell membranes against free radical damage. This study examined the effect of four different treatments including: (1) storage duration after harvest (one and three weeks after harvest); (2) pre-treatment before drying (untreated, pre-treatment with diluted lime juice); (3) drying method (freeze drying (FD) and convective hot air drying (CHAD)); and (4) cultivar (white and red), on the quality of yacon (Smallanthus sonchifolius Poepp. and Endl.) chips in terms of their total phenolic content (TPC) and antioxidant activity (AA) (ABTS (2,2′-Azino-Bis (3-Ethylbenzothiazoline-6-Sulfonic Acid) Diammonium Salt) radical scavenging activity, DPPH (2,2-diphenyl-1-picrylhydrazyl) radical scavenging activity and ferric reducing antioxidant power (FRAP)). Overall, the chips that were produced using pre-treatment with diluted lime juice and FD had the highest amounts of TPC and AA. Regarding the chips produced by means of CHAD, retention of higher TPC and AA was possible with lime-juice pre-treatment and use of higher hot air temperatures. Moreover, chips produced from the white cultivar had higher TPC and AA than chips produced from the red cultivar.


Author(s):  
Catherine Nabbala ◽  
Wunwisa Krasaekoopt

In this study, the antioxidant activity and total phenolic content of Thunbergia laurifolia Lindl. or Rang Chuet (RC) extracts from leaf, stem and rhizome were evaluated by using ferric reducing antioxidant power assay (FRAP) and the folin ciocalteu method for total phenolic compounds (TPC).The extracts were prepared by infusion using different amount of plant powder (2.5, 5.0, and 7.5 g) at different concentrations of ethanol as 0, 25, 50, and 75% and extraction time of 24, 48, and 72 h. The crude extract of 7.5 g leaf powder extracted for 72 h using water as the extraction solvent showed the highest antioxidant properties and total phenolic content. This extraction condition produced a FRAP content of 2.62 ± 0.01 mmol Fe2+/g that was significantly differed from those of the stem and rhizome and the highest TPC content of 877.36±18.75 (mg GAE/g). The crude extract from the leaf was subsequently encapsulated by using β-cylcodextrin (BCD) and maltodextrin 20DE (MD) as coating materials using freeze drying method. The encapsulated powder was investigated for its antioxidant activity. The highest encapsulation efficiency (EE) was obtained when only maltodextrin 20DE was used. The storage stability of encapsulated T. luarifolia leaf crude extract was then studied by storing the encapsulated powder at 35, 45, and 55°C for 5 weeks. The storage temperature had no effect on the stability of the encapsulated powder when TPC was used as the criteria unlike that of FRAP which was inconsistent during storage.


2021 ◽  
Vol 7 (4) ◽  
pp. 242-250
Author(s):  
Nezahat Olcay ◽  
Mine Arslan ◽  
Mustafa Kürşat Demir ◽  
Nilgün Ertaş

In this study, it was aimed to enhanced cake formula-tion with purple carrot pow-der (PCP) dried 3 different methods (hot-air (HPC), microwave (MPC) and vac-uum (VPC) dried) and used at 5 different ratios (0, 5, 10, 15, 20%). The effects of purple carrot powder (PCP) on chemical, physical and sensory properties of cake samples were investigated. HPC substituted cake sam-ples had lower batter densi-ty and weight values. PCP usage significantly affected the crust and crumb color value of cake samples (p<0.05). Samples contain-ing MPC had higher firm-ness and lower springiness than others. Lower firmness, volume index, saturation index and higher springiness values were determined with increasing PCP rate. The highest total phenolic content and antioxidant ac-tivity were found in cake samples containing HPC and VPC, respectively. When all cake samples evaluated, the higher overall acceptability scores were obtained with HPC added cake samples at 15 and 20% substitution level compared to control sample.


2019 ◽  
pp. 42-50 ◽  
Author(s):  
Ahmed Hussein ◽  
Gamil Ibrahim

The present study aimed to evaluate the effect of various bran sources, including wheat, barley, and rice, on the quality and volatile compounds of Egyptian ‘balady’ bread (Fino). The protein, fat, and total carbohydrates content of the studied brans ranged from 8.49 to 14.16%, 2.16 to 8.12%, and 34.38 to 85.06%, respectively. The mi- neral composition and colour parameters of the brans were also evaluated. The substitution of wheat flour with 10%, 20%, and 30% of different brans resulted in decreased loaf volume and specific volume, and increased loaf weight. A significant decrease in colour parameters (L, a, and b) of the bread crust and crumb were observed in all the sam- ples. The addition of bran at three concentrations showed a remarkable increase in the total phenolic content of the bread samples, compared to the control. The antioxidant activity of the bread samples fortified with brans showed the following order: RB (rice bran) > BB (barley bran) > WB (wheat bran), as determined by the DPPH and β-carotene assays. Thirty-six volatile compounds identified in the bread samples using GC-MS included 5 alcohols, 6 pyrazines, 2 acids, 9 aldehydes, 5 ketones, 3 esters, and 6 sulphur-containing compounds. Alcohols were the predominant vola- tile constituents accounting for 58.3; 61.57; 59.08; and 56.15% in the control and in the bread samples prepared with bran from rice, barley, and wheat, respectively.


2019 ◽  
Vol 47 (3) ◽  
Author(s):  
Aylin Celile OLUK ◽  
Atilla ATA ◽  
Mustafa ÜNLÜ ◽  
Ebru YAZICI ◽  
Zafer KARAŞAHİN ◽  
...  

Antioxidant capacity, total phenolic content, colour, sugar, volatiles, ascorbic acid and carotenoid (β-carotene and lycopene) contents of differently coloured and shaped tomato cultivars (cvs) grown in the Eastern Mediterranean region, Turkey were determined, along with a sensory evaluation. Tomato cultivars of two different types (cherry and beefsteak) and four different colours (red, yellow, orange and brown) were analysed. All plants were simultaneously grown in the same field and subjected to identical horticultural practices to minimise the effects of environmental conditions and to maximise those related to genotype. The red cherry cultivar had the highest lycopene content, while the orange beefsteak cultivar had the highest β-carotene content. The highest antioxidant capacity, total phenolic content and hardness scores were found in cherry-type tomatoes, except the yellow one. The red cherry cultivar had the highest sugar content. Red and brown cherry cultivars were also significant in terms of their high carotenoid and sugar contents, along with a high antioxidant activity. The brown cherry cultivar had the highest total phenol content. The highest quantities of 2-hexenal, 3-hexen-1-ol, and 6-methyl-5-hepten-2-one were detected in red cultivars. The brown cherry cultivar had the highest sweetness, typical aroma and hardness scores, while the yellow beefsteak cultivars the lowest sweetness typical aroma scores. In terms of sensory parameters, red and brown cultivars scored higher than yellow and orange ones.   ********* In press - Online First. Article has been peer reviewed, accepted for publication and published online without pagination. It will receive pagination when the issue will be ready for publishing as a complete number (Volume 47, Issue 3, 2019). The article is searchable and citable by Digital Object Identifier (DOI). DOI link will become active after the article will be included in the complete issue. *********


2021 ◽  
Vol 37 (6) ◽  
pp. 1045-1054
Author(s):  
Windi Damayanti ◽  
Meiji Liao ◽  
Yuanrong Xu ◽  
Pu Jing ◽  
Shunshan Jiao

HighlightsHA-RF disinfestation treatment had better pre-drying effect of rough rice than that of HA treatmentHighest moisture loss (8.7%) was obtained for samples with highest IMC (39.6% d.b.)Initial moisture content (IMC) correlated negatively with milling quality of rough riceHA-RF can be used as a pre-drying method to partially reduce the moisture contentAbstract.Hot air-assisted radio frequency (HA-RF) is an environmentally friendly disinfestation method, which can completely control the insects and meanwhile maintain quality of rough rice. In this study, the pre-drying effect of HA-RF disinfestation treatment of rough rice with different initial moisture contents (IMCs) (16.7%, 24.8%, 34.7%, and 39.6% d.b.) was investigated along with associated quality change. HA-RF treatments had better pre-drying effect of rough rice with various IMCs than that of hot air (HA) treatment and larger electrode gap obtained lower moisture removal. IMCs of rough rice also influenced the moisture removal for HA-RF treatments, and the corresponding moisture loss were 4.3%, 5.3%, 6.1%, and 8.7% for the treated rough rice with IMC of 16.7%, 24.8%, 34.7%, and 39.6%, respectively. More quality loss was observed for the rough rice with higher IMC, especially for broken rate, fissure, and water uptake ratio. HA-RF treatment had no influences on total phenolic acids, protein, and fat contents, but amylose and vitamin E contents were affected. Non-milled rice treated by HA-RF had an obvious decrease in the lightness (L*) except for the samples with highest IMC (39.6%). RF disinfestation treatment can be used as a pre-drying method to partially reduce the moisture content (MC) of rough rice. Keywords: Disinfestation, Moisture content, Pre-drying, Quality, Rough rice.


LWT ◽  
2020 ◽  
Vol 131 ◽  
pp. 109754
Author(s):  
Meiji Liao ◽  
Windi Damayanti ◽  
Yuanrong Xu ◽  
Yanyun Zhao ◽  
Xuebing Xu ◽  
...  

Sign in / Sign up

Export Citation Format

Share Document