Prevention of thermal degradation of red currant juice anthocyanins by phenolic compounds addition

The aim of this study was investigation of prevention of thermal degradation of the red currant juice anthocyanins by addition of different phenolic compounds (catechol, 4-methyl catechol, catechin, chlorogenic acid and gallic acid). Phenolic compounds were added in 50:1 and 100:1 copigment:pigment molar ratio. Red currant juice samples were heated at 30, 50, 70 and 90 °C for 1 hour. Thermal degradation of anthocyanins was investigated through determination of anthocyanin content and calculation of the reaction rate constant, half-life of degradation, activation energy and anthocyanin retention. Anthocyanin content ranged from 34.32 mg/100 mL to 47.97 mg/100 mL in a red currant juice, depending on temperature. When phenolic compounds were added anthocyanin content ranged from 34.94 mg/100 mL to 50.41 mg/100 mL, depending on both temperature and added phenolic compounds. In all cases when phenolic compound were added, anthocyanin content, half-lives of degradation increased and the reaction rate constants decreased. The thermal degradation of anthocyanins was lower when phenolic compounds were added due to copigmentation effect. With increase of temperature copigmentation effect was less pronounced. The most contributing phenolic compounds on anthocyanin stability at 30 °C was gallic acid, at 50 °C and 70 °C catechin, and at 90 °C 4-methyl catechol. Concentration of phenolic compounds also had influence on investigated parameters

Physico-chemical Properties of Corn Extrudates Enriched with Tomato Powder and Ascorbic Acid

The aim of this research was to investigate the influence of the addition of tomato powder (TP) to corn grits at levels 4, 6 or 8 % and the addition of ascorbic acid (AA) at levels 0.5 and 1 %, on total polyphenol content (PF), and antioxidant activity of the extrudates. The hardness and the expansion ratio of the extruded products were also tested. Mathematical models that describe the influence of additives on the mentioned properties were also determined. Extrusion was performed at two temperature regimes: 135/170/170 °C and 100/150/150 °C. Lower temperature regime led to increased hardness and the expansion of extrudates. The addition of tomato and AA led to decreased hardness and the expansion at both temperature regimes. The addition of tomato increased PF and AA compared with pure corn extrudates. Greater degradation of PF and AA was at lower temperature regime. High correlation between PF and AA was demonstrated at both extrusion temperatures

High-Voltage Electric Discharge Extraction of Bioactive Compounds from the Cocoa Bean Shell

This study is focused on the application of high-voltage electric discharge (HVED) to recover some bioactive compounds from the cocoa bean shell. Different extraction times (30, 60, 90 min), frequencies (40, 70, 100 Hz) and solvent-solid ratios (10, 30 and 50 mL g–1) were used to obtain cocoa bean shell extracts. Desired bioactive compounds, methylxanthines and phenolic compounds were measured in obtained extracts by high-pressure liquid chromatography with diode array detector. The obtained extracts showed that theobromine was the most abundant, ranging from 2530.13 to 6031.51 mg kg–1, while caffeine content was in the range from 316.08 to 849.88 mg kg–1. In addition, significant amounts of phenolic compounds were found, namely catechin (115.91 to 284.33 mg kg–1), epicatechin (20.20 to 358.90 mg kg–1), and gallic acid (80.28 to 219.17 mg kg–1). Results showed that different parameters of HVED extraction have statistically significant influence on cocoa bean shell composition, suggesting how this byproduct can be used in the production of valuable extracts. This work is licensed under a Creative Commons Attribution 4.0 International License

Effect of galactomannan hydrocolloids on gelatinization and retrogradation of tapioca and corn starch

The aim of the present study was to investigate the effect of galactomannan hydrocolloids (guar gum and locust bean gum) on gelatinization and retrogradation of tapioca and corn starch. Differential scanning calorimetry (DSC) was used to characterize the behaviour of tapioca and corn starch with and without additives. Results showed that guar gum and locust bean gum retarded the retrogradation of tapioca and corn starch at both investigated temperatures (4 and 25 °C). Guar gum retarded retrogradation of tapioca starch more than locust bean gum, on the other hand, locust bean gum had a greater effect on reduction of the recrystallization of corn starch. Temperatures of gelatinization did not vary significantly in starch-hydrocolloid systems. Additions of galactomannan hydrocolloids caused a decrease in gelatinization enthalpy of both starches

Influence of buckwheat and chestnut flour addition on properties of corn extrudates

The aim of this study was to determine the effect of buckwheat and chestnut flour addition to corn meal (ratio meal : flour = 70 : 30, 50 : 50 and 30 : 70) on extrudate properties. Blends (25 % moisture) were extruded at two temperature regimes: 80/90 °C and 75/180 °C. Physical, chemical and rheological properties, and digestibility of the obtained extrudates were investigated in relation to non extruded samples. Addition of chestnut flour to corn meal resulted in increase of fibre, ash and fat content, and decrease of protein content, while buckwheat flour addition resulted in increase of all measured components. Chestnut and buckwheat flour addition increased whiteness and decreased yellowness of non-extruded samples. While extrusion of corn meal resulted in increase of whiteness, extrusion of both types of mixtures resulted in its decrease. Bulk density increased and expansion ratio, hardness and fracturability decreased by addition of chestnut and buckwheat flour. Extrusion of all investigated samples resulted in decrease of peak, hot and cold viscosity and increase of water absorption index. Total polyphenol content and antioxidant activity increased by the addition of buckwheat and chestnut flour, but the extrusion caused their decrease

Influence of high intensity ultrasound on rheological and pasting properties of wheat starch

Svrha ovog rada je ispitati utjecaj ultrazvuka visokog i niskog intenziteta na reološka i pastozna svojstva suspenzija škroba pšenice. Ispitivane suspenzije sadrže 10 % pšeničnog škroba te su neposredno nakon pripreme procesirane ultrazvukom. Sva ispitivanja provedena su prije i nakon ultrazvučne obrade u ultrazvučnoj kupelji frekvencije 22 kHz, nominalne snage 150 W te ultrazvučnom sondom frekvencije 24 kHz, nominalne snage 100, 300 i 400 W. Vrijeme ultrazvučne obrade svih uzoraka bilo je 15 i 30 minuta. Reološka svojstva određena su primjenom rotacionog reometra Rheometric Scientific RM-180 pri temperaturi od 20 ˚C, a pastozna svojstva škrobnih suspenzija određena su primjenom Micro Visco-Amylo-Graph, Brabender Ohg Duisburg, Njemačka po metodi ICC Standard 126/1. Ultrazvučna obrada uzrokuje mehaničko oštećenje škrobne granule čime njena unutrašnjost postaje dostupnija vodi tijekom zagrijavanja što ima za posljedicu značajne promjene reoloških i pastoznih svojstava škrobnih suspenzija. Reološki parametri pokazuju da sve suspenzije imaju ne-Newtonski karakter, a ultrazvučni tretmen uzrokovao je značajno povećanje koeficijenta konzistencije svih ispitivanih sustava. Ultrazvučnim procesiranjem došlo je do značajnog sniženja temperature želatinizacije kod svih škrobnih suspenzija. Značajno smanjenje početnih temperatura želatinizacije upućuje na raniji stupanj bubrenja granule tijekom zagrijavanja.The aim of this paper was to examine the influence and effect of high and low power ultrasound on rheological and thermophysical properties of wheat starch suspensions. Suspensions containing ten percent of potato starch have been treated with ultrasound. All analysis have been carried out before and after power ultrasound treatment. Ultrasound bath of 22 kHz frequency and nominal power of 150 W has been used, as well as ultrasound probe of 24 kHz frequency and nominal power of 100, 300 and 400 W for 15 and 30 minute treatments. Rheological parameters have been determined with rheometer Rheometric Scientific RM-180 at 20 ºC. Pasting properties have been determined with Micro Visco-Amylo-Graph, Brabender Ohg Duisburg at method ICC Standard 126/1. Ultrasonic treatment caused disrupting of starch granules by mechanical forces and made the granule more permeable to water during the heating step. Because, significant changes of rheological and pasting properties were observed. Rheological parameters showed that all suspensions exhibited non-newtonian (dilatant) character. Also, ultrasonic treatment has affected a significant increase of consistency coefficient of starch suspension. Ultrasonic treatment caused significant lowering of the beginning gelatinization temperatures, which indicated an earlier state of granule swelling during heating

Chemical risk factors responsible for the formation of wedge-shaped lesions

Introduction: Non-carious tooth substances loss pose a major health problem of a modern man. The literature often collectively describes all non-carious lesions and is therefore difficult to compare results obtained by different authors. Chemical factors are one of the predisposing factors responsible for the formation of wedge-shaped erosions. Aim: Examination of chemical risk factors as one of the predisposing causes responsible for the formation of wedge-shaped lesions. Method: We examined 62 patients with wedge-shaped erosions (mean age 45.52 ± 12.03 years, 58.1% of men) and 60 patients without erosions in the control group (mean age 34.40 ± 9.28 years, 60% men) . The entire examination was completed by using a questionnaire at the Dental Clinic of the University of Pristina - Kosovska Mitrovica. salivary pH was measured by the pH meter. Results: The results show that the wedge-shaped lesions often occur equally in both men and women. Considerably often it might appear in older people but can also occur in teenagers. Patients with wedge-shaped erosion have increased acidity of saliva, a heightened sense of acid in the mouth and consume a lot more carbonated drinks compared to patients without erosions. Conclusion: Wedge-shaped lesions are more common in people older than 40 years. Taking into account the results obtained in this study it can be concluded that the chemical risk factors truly fall within the predisposing factors that may be responsible for the creation of wedge-shaped erosions

The effects of the fermentation with immobilized yeast and different cherry varieties on the quality of cherry brandy

The aim of this research was to investigate influence of different fermentation processes (by immobilized yeast cells and classical fermentation) and different cherry varieties (Maraska, Montmorencys and Kelleris) on the chemical and sensorial characteristics of cherry brandies. Cherry brandies were analyzed to determine chemical composition, aroma profile and sensory properties. Cherry brandies produced by immobilized yeast cells had a higher content of aldehydes, but lower content of total acids, total extract, higher alcohols and esters compared to the samples produced by classical fermentation process. Furfural was not detected in cherry distillates produced by immobilized yeast cells, while distillates produced by classical fermentation process had very low content. Cherry brandies produced by classical fermentation process had significantly higher content of benzaldehyde which has great influence on aroma of cherry brandies. Ethyl octanoate which is considered one of the most important contributors to the aroma of alcoholic distillates was found in the highest concentrations in Maraska distillates. The best evaluated sample was brandy produced from Maraska cherry variety fermented by immobilized yeast cells followed by brandy produced also from Maraska cherry variety, but by classical fermentation process

Cold Pressing and Supercritical CO2 Extraction of Hemp (Cannabis sativa) Seed Oil

In the past few decades, the Cannabis sativa L. hemp variety has been unfairly neglected because of its similarity to the illegal kind Cannabis indica used as a narcotic. The objective of this study was to evaluate the process of oil extraction from Cannabis sativa seeds by cold pressing, followed by extraction with supercritical CO2. In the pressing experiments, the response surface methodology was conducted in order to study the effects of temperature, frequency, and nozzle size on oil recovery and quality parameters. The optimal condition for obtaining the highest oil recovery (23.34 %) and the best oil quality within the experimental range of the variables studied was at temperature of 60 °C, frequency of 20 Hz, and nozzle of ID 6 mm. The residual oil (10.33 %) in the press cake was extracted totally by supercritical CO2 in a newly designed supercritical fluid extraction system. Oregano essential oil was the most effective in protecting the oil from oxidative deterioration