scholarly journals Effect of Dehydration on Several Physico-Chemical Properties and the Antioxidant Activity of Leeks (Allium porrum L.)

2011 ◽  
Vol 39 (1) ◽  
pp. 144 ◽  
Author(s):  
Mehmet OZGUR ◽  
Arzu AKPINAR-BAYIZIT ◽  
Tulay OZCAN ◽  
Lutfiye YILMAZ-ERSAN
Keyword(s):  
Antioxidant Activity ◽  
Dry Matter ◽  
Chemical Properties ◽  
Effect Of Temperature ◽  
Allium Porrum ◽  
Drying Process ◽  
Hot Air Drying ◽  
Air Drying ◽  
Hot Air ◽  
Physico Chemical

This study investigated the changes in some physico-chemical properties and variations in antioxidant compounds of leeks (cv. ‘Inegol-92’) caused by the drying process. The dry matter and ash contents of the fresh leek samples were 8.06 and 0.58 g 100 g-1, respectively. The pH of the fresh leek samples was 6.02, and the titritable acidity in terms of citric acid was 0.14%. As expected, application of hot-air drying significantly increased the dry matter and ash values due to removal of water from the leek slices. The rehydration ratio of dried leeks at 45°C was 5.41, and the coefficient of rehydration was 0.47. The contents of chlorophyll a and b were higher in the dried leeks than in the fresh leeks. The dehydrated leeks showed a high total color difference (?E=12.53) mainly due to the effect of temperature on heat-sensitive compounds. As expected, both fresh and dried leek samples exhibited antioxidant activity with fresh leeks showing a higher capacity of antioxidant activity. Drying the leeks resulted in some ascorbic acid loss. Fresh leeks had much higher phenolic values (26.33 mg rutin eq 100 g DM-1) than the dehydrated samples. The antioxidant capacity of leeks was decreased by more than 50% during the drying process. Although being the most applied method of thermal dehydration, hot air drying causes the degradation of sensitive components, which results in significant losses in sensorial and physico-chemical properties of the dried products.

Determination of Antioxidant Activity of Edible Calendula Flowers by Hot-air Drying Time

2018 ◽  
Vol 26 (4) ◽  
pp. 202-208
Author(s):  
Sang Im Oh ◽  
Seo Young Kim ◽  
Ja Hee Lee ◽  
Ae Kyung Lee
Keyword(s):  
Antioxidant Activity ◽  
Hot Air Drying ◽  
Drying Time ◽  
Air Drying ◽  
Hot Air

Experimental Study on Hot-air Drying Process Parameters Optimization of Chinese Jujubes

2013 ◽  
Vol 12 (21) ◽  
pp. 6154-6158
Author(s):  
Xiao Kang-Yi ◽  
Chuan Feng-Li ◽  
Shu Gang-Li ◽  
He Lei Cui ◽  
Wen Fu-Wu
Keyword(s):  
Experimental Study ◽  
Process Parameters ◽  
Parameters Optimization ◽  
Drying Process ◽  
Hot Air Drying ◽  
Air Drying ◽  
Process Parameters Optimization ◽  
Hot Air

scholarly journals Changes in Aroma Profile of Shiitake Mushroom (Lentinus edodes) during Different Stages of Hot Air Drying

Foods ◽  
2020 ◽  
Vol 9 (4) ◽  
pp. 444 ◽  
Author(s):  
Lei Qin ◽  
Jing-Xuan Gao ◽  
Jia Xue ◽  
Dong Chen ◽  
Song-Yi Lin ◽  
...  
Keyword(s):  
Volatile Compounds ◽  
Sensory Evaluation ◽  
Early Stage ◽  
Organosulfur Compounds ◽  
Lentinus Edodes ◽  
Drying Process ◽  
Shiitake Mushroom ◽  
Hot Air Drying ◽  
Air Drying ◽  
Hot Air

To clarify the changes in the aroma characteristics of shiitake mushrooms (Lentinus edodes) during hot-air drying, volatile compounds of L. edodes were analyzed using sensory evaluation, electronic nose, and purge and trap combined with gas chromatography-mass spectrometry (PT-GC-MS) at different timepoints of the drying process. Results showed that the sensory and volatile profile changed significantly during the drying process at 60 °C for up to 12 h and the drying process could be divided into three stages: early stage (<2 h), middle stage (2–3.5 h) and late stage (>3.5 h). Volatile compounds in fresh L. edodes consisted mainly of ketones and alcohols. The early stage of drying decreased the concentration of ketone and alcohol compounds and promoted the generation of cyclic organosulfur compounds through a series of enzymatic and non-enzymatic reactions, which mainly contribute to the characteristic odor of shiitake mushroom. Partial least squares-discriminant analysis (PLS-DA) showed that the volatile compounds released after different drying times could be divided into four groups, which have been confirmed by sensory evaluation results. The results suggested that the unique flavor of dried mushrooms is mainly due to the activation of enzymes during the drying process, which act on lentinic acid to produce sulfur-containing heterocyclic compounds. We believe that our study makes a potential contribution to the mushroom cultivation and processing industry to achieve an improvement in sensory quality.

Quality Characterization of Waste Olive Cake During Hot Air Drying: Nutritional Aspects and Antioxidant Activity

2012 ◽  
Vol 6 (5) ◽  
pp. 1207-1217 ◽  
Author(s):  
Elsa Uribe ◽  
Roberto Lemus-Mondaca ◽  
Antonio Vega-Gálvez ◽  
Lorena A. López ◽  
Karina Pereira ◽  
...  
Keyword(s):  
Antioxidant Activity ◽  
Olive Cake ◽  
Hot Air Drying ◽  
Air Drying ◽  
Hot Air

scholarly journals The Effect of Different Extraction Protocols on Brassica oleracea var. acephala Antioxidant Activity, Bioactive Compounds, and Sugar Profile

Plants ◽  
2020 ◽  
Vol 9 (12) ◽  
pp. 1792
Author(s):  
Nikola Major ◽  
Bernard Prekalj ◽  
Josipa Perković ◽  
Dean Ban ◽  
Zoran Užila ◽  
...  
Keyword(s):  
Antioxidant Activity ◽  
Freeze Drying ◽  
High Energy ◽  
Total Phenolic ◽  
Glucosinolate Content ◽  
Aqueous Methanol ◽  
Hot Air Drying ◽  
Air Drying ◽  
Hot Air ◽  
Sugar Profile

The extraction of glucosinolates in boiling aqueous methanol from freeze dried leaf tissues is the most common method for myrosinase inactivation but can be hazardous because of methanol toxicity. Although freeze drying is the best dehydration method in terms of nutritional quality preservation, the main drawbacks are a limited sample quantity that can be processed simultaneously, a long processing time, and high energy consumption. Therefore, the aim of this study is to evaluate the effects of applying high temperature for myrosinase inactivation via hot air drying prior to the extraction step, as well as the effects of cold aqueous methanol extraction on total antioxidant activity, total glucosinolates, total phenolic content, and sugar profile in 36 landraces of kale. The results from our study indicate that cold aqueous methanol can be used instead of boiling aqueous methanol with no adverse effects on total glucosinolate content. Our results also show that hot air drying, compared to freeze drying, followed by cold extraction has an adverse effect on antioxidant activity measured by DPPH radical scavenging, total glucosinolate content, as well as on the content of all investigated sugars.

Preparation of potato flour by freeze-thaw pretreatment: Effect of different thawing methods on hot-air drying process and physicochemical properties

LWT ◽  
2020 ◽  
Vol 133 ◽  
pp. 110157
Author(s):  
Guanghui Shen ◽  
Lidan Zhang ◽  
Tingting Hu ◽  
Zhihong Li ◽  
Anjun Chen ◽  
...  
Keyword(s):  
Physicochemical Properties ◽  
Potato Flour ◽  
Drying Process ◽  
Hot Air Drying ◽  
Air Drying ◽  
Freeze Thaw ◽  
Hot Air ◽  
Pretreatment Effect
Sign in / Sign up

Export Citation Format

Share Document