Hydrothermal treatment of sugars to obtain high-value products

Gagić, Tanja; Perva-Uzunalić, Amra; Knez, Željko; Škerget, Mojca

doi:10.2298/jsc181218070g

Cited by 5 publications

(4 citation statements)

References 14 publications

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“…20 Furthermore, sugars and their derivatives are also the products of hydrothermal hydrolysis of chestnut tannins, which have high potentials in fuel and polymer applications and applications in many industries (pharmaceutical, agrochemical, flavour, fragrance and food). 21 There are a few articles that are based on the study of the composition of chestnut tannins 10,[22][23][24] and their hydrolysis, 17 but there is no comparable study dealing with subcritical water treatment of chestnut tannins. Furthermore, acid hydrolysis was also made in order to compare these two methods.…”

Section: Introductionmentioning

confidence: 99%

Hydrothermal hydrolysis of sweet chestnut (Castanea sativa) tannins

Gagić

Knez

Škerget

2020

JSCS

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Sweet chestnut tannins were treated with subcritical water at temperatures from 120 to 300 °C for reaction times of 15, 30 and 60 min. A great influence of temperature and reaction time on the product yield was noticed. Spectrophotometric methods were used to determine the total tannins, phenols and carbohydrates contents and antioxidant activity. Furthermore, vescalin, castalin, vescalagin, castalagin, 1-O-galloyl castalagin, gallic, ellagic and ferulic acids were analysed by HPLC. The results obtained from hydrothermal hydrolysis were compared to results from acid hydrolysis. Finally, the reaction parameters of the hydrothermal hydrolysis process were optimized aimed at obtaining a product with a high concentration of ellagic acid. The optimal conditions for obtaining the highest concentration of ellagic acid of 29.55 % were 250 °C and 5 min. The concentration of ellagic acid in tannin extract obtained by acid hydrolysis was 8.19 %.

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Section: Introductionmentioning

confidence: 99%

Hydrothermal hydrolysis of sweet chestnut (Castanea sativa) tannins

Gagić

Knez

Škerget

2020

JSCS

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“…Similar to xylose, lactose was not detected in the extract resulting from the hydrothermal treatment (Table 4). Lactose is a dimer resulting from the union of glucose and galactose molecules, and hydrothermal treatment may not be suitable for its formation [27]. However, the L/L extraction process probably facilitated their bonding, leading to the formation of lactose molecules during this process.…”

Section: Xylose Fructose Lactose and Sucrosementioning

confidence: 99%

Optimizing the Extraction Process of Value-Added Products from Olive Cake Using Neuro-Fuzzy Models

Lozano,

Blázquez,

Calero

et al. 2024

Processes

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The use of olive cake, an abundant residue in the olive oil industry, has been studied by developing a biorefinery scheme. The aim was to develop a novel, efficient, and environmentally friendly strategy for the valorization of olive cake, contributing to sustainable agriculture. A special extraction procedure based on a combination of hydrothermal treatments with liquid/liquid extractions was designed to produce value-added products, along with solids that can be used for energy or adsorbent production. The optimal extraction conditions were determined by exploring the influence of the operating variables (temperature, extraction time, solvent type, solvent/extract ratio, extraction stages, and pH) on the extraction yield. The decision about the optimal conditions was made by adjusting the experimental results to a neuro-fuzzy model. Glucose and inositol showed similar response surfaces, allowing simultaneous concentration in a single process. Under optimal extraction conditions, the concentration of inositol increased by up to 70%, while glucose and fructose increased by 70 and 30 times, respectively, compared to the initial feed. The proposed methodology successfully extracted significant amounts of bioactive polyols (mainly inositol) (1126 mg/L), saccharides (15,960 mg/L glucose, 385 mg/L xylose, 5550 mg/L fructose, 165 mg/L lactose, and 248 mg/L sucrose), and polyphenols (4792 mg/L) under mild conditions, i.e., 30 °C and 30 min. Thus, olive cake extracts have a great unexploited potential for application in several industrial sectors, including, but not limited to, food and pharmaceuticals.

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“…The products obtained were quantified using the calibration curves of standards. The results were expressed in mg compound/g extract [48].…”

Section: Hplc Analysismentioning

confidence: 99%

“…In conventional extraction, the maximum glucose concentration was detected in the extract from pistachio shells (6.3 mg/g extract), which was obtained with 50% acetone. Glucose is converted to fructose in subcritical water by an isomerization reaction [48]. The highest amount of fructose (117.10 mg/g extract) in the extract from walnut shells was achieved at 250 • C and 15 min.…”

Section: Sugars and Derivativesmentioning

confidence: 99%

The Conversion of Pistachio and Walnut Shell Waste into Valuable Components with Subcritical Water

Čolnik,

Irgolič,

Perva

et al. 2024

Processes

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Pistachio and walnut shells accumulate in large quantities as waste during food processing and represent a promising lignocellulosic biomass for the extraction of valuable components. Subcritical water technology was used as an environmentally friendly technique to study the extraction of active ingredients and other valuable degradation products from walnut and pistachio waste. Subcritical water extraction (SWE) was carried out under different process conditions (temperature (150–300 °C) and short reaction times (15–60 min)) and compared with conventional extraction using different organic solvents (acetone, 50% acetone and ethanol). The extracts obtained from pistachio and walnut shell waste are rich in various bioactive and valuable components. The highest contents of total phenols (127.08 mg GA/g extract at 300 °C for 15 min, from walnut shells), total flavonoids (10.18 mg QU/g extract at 200 °C for 60 min, from pistachio shells), total carbohydrates (602.14 mg TCH/g extract at 200 °C for 60 min, from walnut shells) and antioxidant activity (91% at 300 °C, for 60 min, from pistachio shells) were determined when the extracts were obtained via subcritical water. High contents of total phenols (up to 86.17 mg GA/g extract) were also determined in the conventional extracts obtained with ethanol. Using the HPLC method, sugars and their valuable derivatives were determined in the extracts, with glucose, fructose, furfurals (5-hydroxymethylfurfural (5-HMF) and furfural) and levulinic acid being the most abundant in the extracts obtained by subcritical water. The results show that subcritical water technology enables better exploitation of biowaste materials than conventional extraction methods with organic solvents, as it provides a higher yields of bioactive components such as phenolic compounds and thus extracts with high antioxidant activity, while at the same time producing degradation products that are valuable secondary raw materials.

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Hydrothermal treatment of sugars to obtain high-value products

Cited by 5 publications

References 14 publications

Hydrothermal hydrolysis of sweet chestnut (Castanea sativa) tannins

Hydrothermal hydrolysis of sweet chestnut (Castanea sativa) tannins

Optimizing the Extraction Process of Value-Added Products from Olive Cake Using Neuro-Fuzzy Models

The Conversion of Pistachio and Walnut Shell Waste into Valuable Components with Subcritical Water

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