scholarly journals The nutritional potential of grape by-products from the area of Slovakia and Austria

Author(s):  
Ondrej Hanušovský ◽  
Branislav Gálik ◽  
Daniel Bíro ◽  
Milan Šimko ◽  
Miroslav Juráček ◽  
...  

Current experiments with farm animals showed that it is possible to use grape by-products as a source of nutrients in animal nutrition. In the present experiment, we hypothesize that one reason for the variation among feeding trials, besides production steps affecting byproduct quality in winery, the variation among cultivars may have substantial contribution. The main aim of this study was to analyse grape pomace and stems from the area of Slovak Republic and Austria to evaluate their nutritional value for animals. In total, 54 samples of 3 grape varieties from 6 different locations were analysed. In each variety basic nutrients, antioxidant activity, total phenols, condensed tannins and proteins participation was determined according to standard analytical methods. The results show that the grape pomace had the highest ratio of crude proteins, crude fat and crude fibre with the solid concentrations of sugars, except of variety from red grape. Then, the grape stem is characterised with balanced content of crude protein, crude fibre and nitrogen free extracts with residual sugars and the highest antioxidant activity. By-products from the winery production have average nutritional value because of higher content of lignin that could be limiting factor for the digestibility. Neverthelles, there are interactions between the fibre fractions, condensed tannins, total polyphenols and antioxidant activity. Analysed data shows, that grape by-products have a potential in animal nutrition as a source of bioactive compounds, however there exists differences between the locations and varieties.

Author(s):  
Aida Mekhoukhe ◽  
Houda Kicher ◽  
Adidi Ladjouzi ◽  
Lamia Medouni-Haroune ◽  
Fatiha Brahmi ◽  
...  

Abstract Background The carob (Ceratonia siliqua L.) is very old edible fruit, flavorful and often used in foods and beverages. In this present study the composition of phenolic compounds, the antioxidant activity and the production locust bean gum (LBG) of seeds grown in Algeria was explored. Methods The phenolic contents (total phenolics, total tannins, total flavonoids, condensed tannins and flavonols) and the antioxidant activity of the aqueous methanolic, ethanolic and acetonic extracts (70, 80 and 80v/v, respectively) of the seeds were determined using colorimetric methods. Furthermore, the carob bean gum from seeds was extracted and its chemical composition was evaluated. Results Aqueous acetonicextract of carob seeds give the highest contents of total phenolics, total flavonoids, flavonols, total tannins and condensed tannins which were 12.24±0.02, 1.33±0.01, 2.97±0.01, 4.29±0.2 and 0.53±0.01 mg/g of dry weight, respectively. The same extract showed also the best antioxidant activity in all assays compared to other extracts.


2010 ◽  
Vol 39 (12) ◽  
pp. 1826-1831 ◽  
Author(s):  
Ji-Eun Jo ◽  
Hong-Sun Yook ◽  
Kyoung-Hee Kim ◽  
Jong-Yeon Baek ◽  
Young-Ja Moon ◽  
...  

2019 ◽  
Vol 16 (3) ◽  
pp. 194-201 ◽  
Author(s):  
Renu Bala ◽  
Vandana Devi ◽  
Pratibha Singh ◽  
Navjot Kaur ◽  
Pawandeep Kaur ◽  
...  

Background: Tetrahydroindazole, a member of the fused-pyrazole system, is a least studied class of heterocyclic compounds owing to its scarcity in nature. However, a large number of synthetically prepared tetrahydroindazoles are known to show a variety of biological activities such as interleukin- 2 inducible T-Cell kinase inhibitors, AMPA receptor positive allosteric modulators, antitumor, antituberculosis, anti-inflammatory and antimicrobial activities. Vilsmeier-Haack reaction is one of the most important chemical reactions used for formylation of electron rich arenes. Even though Vilsmeier- Haack reaction was studied on a wide variety of hydrazones derived from active methylene compounds, literature lacks the examples of the use of 4-substituted cyclohexanones as a substrate for the synthesis of 4,5,6,7-tetrahydroindazoles. The study of the reaction of Vilsmeier-Haack reagent with hydrazones derived from cyclic keto compounds having active methylene has been considered the interested topic of investigation. In the present study, ethyl cyclohexanone-4-carboxylate was treated with one equivalent of various hydrazines for two hours and the resulted hydrazones were further treated with an OPC-VH reagent (Vilsmeier-Haack reagent isolated from phthaloyl dichloride and N,Ndimethylformamide) afforded 4,5,6,7-tetrahydroindazoles in excellent yields. The synthesized compounds 4a-f and 5a-f were screened for their antioxidant activities using the DPPH radical scavenging assay. The target compounds were synthesized regioselectively using 4+1 approach in excellent yields. A number of experiments using both conventional heating as well as microwave irradiation methods were tried and on comparison, microwave irradiation method was found excellent in terms of easy work up, high chemical yields, shortened reaction times, clean and, no by-products formation. Some of the synthesized compounds showed significant antioxidant activity. The microwave assisted synthesis of 4,5,6,7-tetrahydroindazoles from ethyl cyclohexanone-4-carboxylate has been reported under mild conditions in excellent yield. Easy work up, high chemical yield, shortened reaction times, clean and no by-products formation are the major advantages of this protocol. These advantages may make this method useful for chemists who are interested in developing novel 4,5,6,7-tetrahydroindazole based drugs.


Author(s):  
Sara Díaz ◽  
Antonio N. Benítez ◽  
Sara Ramírez-Bolaños ◽  
Lidia Robaina ◽  
Zaida Ortega

AbstractThe aim of this work is the optimization of phenolic compound extraction from three by-products of banana crops (rachis, discarded banana, and banana’s pseudostem pulp), as a way to valorize them through a green extraction process. The influence of the temperature and aqueous ethanol concentration (Et-OH) on extract properties (total phenol content (TPC) and antioxidant activity) was firstly analyzed. 78 ℃ and ethanol concentrations close to 50% yielded the best results for the three materials. The equations obtained by the response surface methodology gave a satisfactory description of the experimental data, allowing optimizing the extraction conditions. Under optimized conditions, time influence was then assessed, although this parameter seemed not influence results. Among the three by-products, rachis extract (60% Et-OH, 78 ℃, and 30 min) presented the highest TPC (796 mg gallic acid/100 g of dried material) and antioxidant activity (6.51 mg Trolox equivalents/g of dried material), followed by discarded banana, and pseudostem pulp. Under the optimal conditions, experiments were performed at a larger scale, allowing to determine the extraction yields (EY) and to characterize the extracts. The highest EY was obtained for the rachis (26%), but the extract with the highest activity was obtained for discarded banana (50% Et-OH, 78 ℃, and 60 min), which presented a TPC of 27.26 mg/g extract corresponding to 54.59 mg Trolox equivalents/g extract. This study contributes to the valorization of banana crops residues as a source of polyphenolic compounds with bioactive functions that can be extracted under economic extraction conditions. Graphical abstract


Animals ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 196
Author(s):  
Elisa Varona ◽  
Alba Tres ◽  
Magdalena Rafecas ◽  
Stefania Vichi ◽  
Ana C. Barroeta ◽  
...  

Acid oils (AO) and fatty acid distillates (FAD) are oil refining by-products rich in free fatty acids. The objective of this study is their characterization and the identification of their sources of variability so that they can be standardized to improve their use as feed ingredients. Samples (n=92) were collected from the Spanish market and the MIU value (sum of moisture, insoluble impurities, and unsaponifiable matter), lipid classes, fatty acid composition, and tocol content were analyzed. Their composition was highly variable even between batches from the same producer. As FAD originated from a distillation step, they showed higher free fatty acid amounts (82.5 vs 57.0 g/100 g, median values), whereas AO maintained higher proportions of moisture, polymers, tri-, di-, and monoacylglycerols. Overall, the MIU value was higher in AO (2.60–18.50 g/100 g in AO vs 0.63-10.44 g/100 g in FAD), with most of the contents of insoluble impurities being higher than those in the guidelines. Tocol and fatty acid composition were influenced by the crude oil’s botanical origin. The calculated dietary energy values were, in general, higher for AO and decreased when a MIU correction factor was applied. The analytical control and standardization of these by-products is of the outmost importance to revalorize them as feed ingredients.


Antioxidants ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 1207
Author(s):  
Shu-Cheng Duan ◽  
Soon-Jae Kwon ◽  
Seok-Hyun Eom

The leaves and seeds of the faba bean are good sources of L-3,4-dihydroxyphenylalanin (L-dopa), and are usually eaten with thermal cooking methods. However, little information is available on the effect of thermal treatments on their nutritional value. We compared the changes in color, contents of L-dopa, vitamin C (Vc), total phenolics (TP), total flavonoids (TF) and antioxidant activity after dry heating or steaming faba bean leaves and seeds. The young leaves provided higher values of all the estimate factors, regardless of the thermal treatment. Steaming significantly degraded nutritional values of the leaves, but less changed in seeds, whereas dry heat maintained these attributes. The contents of L-dopa, Vc, TP and TF were shown to have strongly positive correlations with antioxidant activity in the leaves, whereas only L-dopa content was positively correlated with antioxidant activity of the seeds. Faba leaves contained relatively high L-dopa which possessed strong antioxidant activity compared to the Vc. As L-dopa is an important contributor to the antioxidant activity of faba leaves and seeds, consuming L-dopa from leaves may provide beneficial effects not only regarding Parkinson’s Disease.


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