scholarly journals Thermal Stability and Inhibitory Action of Red Grape Skin Phytochemicals against Enzymes Associated with Metabolic Syndrome

Antioxidants ◽  
2022 ◽  
Vol 11 (1) ◽  
pp. 118
Author(s):  
Daniela Serea ◽  
Nina Nicoleta Condurache ◽  
Iuliana Aprodu ◽  
Oana Emilia Constantin ◽  
Gabriela-Elena Bahrim ◽  
...  

The present study focuses on heat-induced structural changes and the degradation kinetics of phytochemicals and antioxidant activity of red grape skin extract. The thermal degradation of anthocyanins, flavonoids, polyphenols, and antioxidant activity followed a first-order kinetic model, increasing with temperature due to the intensification of the degradation process. The activation energy (Ea) highlighted this phenomenon. Likewise, the kinetic and thermodynamic parameters certified the irreversible degradation of the bioactive compounds from the skin of the Băbească neagră grape variety. Both temperature and duration of heating had a significant impact on the content of bioactive compounds. In addition, the red grape skin extract inhibited certain enzymes such as α-amylase, α-glucosidase, lipase, and lipoxygenase, which are associated with metabolic syndrome and inflammation. Further knowledge on the possible inhibition mechanisms exerted by the major anthocyanins found in red grape skin extract on the metabolic syndrome-associated enzymes was gathered upon running molecular docking tests. Detailed analysis of the resulting molecular models revealed that malvidin 3-O-glucoside binds in the vicinity of the catalytic site of α-amylase and lipase, whereas no direct contact with catalytic amino acids was identified in the case of α-glucosidase and lipoxygenase.

Author(s):  
Arkadiusz Szpicer ◽  
Anna Onopiuk ◽  
Iwona Wojtasik-Kalinowska ◽  
Andrzej Półtorak

AbstractConsumers are increasingly interested in innovative products enriched with nutrients that counteract the development of civilisation-associated diseases. Thus, the development of new functional nutrient-enriched food products that meet consumer needs is therefore necessary. The aims of this study were to develop a novel shortbread cookie product by addition of red grape skin extract and oat β-glucan and to evaluate the influence of these modifications on physico‐chemical properties and consumer’s acceptance. The red grape skin extract used in this product is a source of polyphenols which are beneficial for human health and extend product shelf life. β-glucan is a soluble fraction of dietary fibre that helps to lower reduce blood cholesterol and glycemic levels. The influence of grape skin extract, β-glucan and a combination of both on the β-glucan content, colour and texture parameters, thermal properties, total antioxidant activity, total phenolic content, volatile compounds profile and sensory properties of shortbread cookies was analysed. Product with modified formulations had higher total antioxidant activity, total phenolic content and were was more thermally stable than control samples. The obtained innovative functional products were characterized by an increased content of oat β-glucan, which is desirable from a nutritional point of view. The DSC measurements showed higher oxidative stability of cookies enriched with β-glucan and red grape skin extract. The additives caused significant changes in the colour and profile of volatile compounds of the finished final product but did not affect the sensory acceptance among consumers. The use of these additives represents a development in food technology that may be valuable in the food industry to increase the nutritional value and extend the shelf shelf-life of bakery products.


1967 ◽  
Vol 50 (2) ◽  
pp. 293-299 ◽  
Author(s):  
J Fitelson

Abstract Paper chromatography of the anthocyanidins, the phenolic components of the anthocyanins, is the most satisfactory means of detecting adulteration of Concord grape juice with other red grape juice and colored Italian grape skin extract. The 5 aniliocyanidins found in grape colors can be readily separated into 3 spots by paper chromatography. In the proposed method, anthocyanins are separated by lead precipitation, dissolved in water, and acid-hydrolyzed to obtain the anthocyanidins. Thirty Concord samples, 7 red grape juice samples, and 5 Italian grape skin extracts were examined and results were good. Four unknown samples were analyzed by 5 collaborators; all collaborators correctly detected the adulterated sample and the pure Concord sample. This method was recommended for adoption as official, first action


2008 ◽  
Vol 41 (4) ◽  
pp. 662-675 ◽  
Author(s):  
Przemysław Koźmiński ◽  
Ana Maria Oliveira‐Brett

Author(s):  
Daniela Serea ◽  
Gabriela Râpeanu ◽  
Oana Emilia Constantin ◽  
Gabriela Elena Bahrim ◽  
Nicoleta Stănciuc ◽  
...  

The phenolic composition of the skin of the Băbească neagră grapes grown in south-eastern Romania was studied by two extraction techniques, i. e., ultrasound-assisted extraction (UAE) and enzyme-assisted extraction (EAE). This study aimed to analyze the grape skin bioactive compounds and the antioxidant potential using ethanol of three different concentrations 50%, 70%, and 96% and acidified with acetic, citric acid, or hydrochloric acid. This research aimed to maximize the extraction of bioactive compounds from red grape skin by using commercially available oenological enzyme preparations, varying the enzyme dosage, pH, temperature and extraction time. The results indicated that the highest total anthocyanin content was obtained when using 70 % ethanol extract acidified with 0.1 N hydrochloric acid, characterized by 4.29±0.04 mg C3G/g DW for ultrasound extraction and 2.54±0.13 for enzyme-assisted extraction. The results of antioxidant potential of the extracts investigated showed that the 96% ethanol extract had the highest antioxidant activity (18.76±0.24 mM of Trolox/g DW), followed by the 50% ethanol extract and 70% ethanol extract (16.35±0.79 and 16.48±0.54 mM of Trolox/g DW, respectively). The results disclosed that the highest extraction yield for antioxidant activity quantification was obtained by cellulase (61.48±1.19 mMol Trolox / g DW) after only one hour of extraction.


Diabetes ◽  
2019 ◽  
Vol 68 (Supplement 1) ◽  
pp. 88-LB
Author(s):  
MEIS ALKASEM ◽  
IBRAHEM ABDALHAKAM ◽  
NOOR N. SULEIMAN ◽  
AHMAD NABIL ISKANDARANI ◽  
TAREQ A. SAMRA ◽  
...  

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