scholarly journals Changes during the extrusion of semolina in mixture with sugars

2013 ◽  
Vol 19 (No. 1) ◽  
pp. 24-30 ◽  
Author(s):  
A. Farouk Mansour ◽  
F. Pudil ◽  
V. Janda ◽  
J. Pokorný

Wheat semolina and its mixtures with 5% glucose, fructose of sucrose were processed in a sigle screw extruder at the maximum temperature of 140°C and the processing time of 30 s. The nonenzymic browning was only moderate, but it was substantially more intensive in mixtures with glucose or fructose than in the case of wheat semolina or its mixture with sucrose. Red and yellow pigments were mainly formed. The odour acceptability was affected by the presence of sugars almost negligibly, but the intensities were different, higher in extruded mixtures with glucose and fructose than in wheat semolina or its mixture with sucrose. Small differences were observed in the sensory profile. Extrusion of semolina with sugars produced more sensory active volatiles (52–69 identified compounds) than in extruded semolina (41 compounds). Pyrazines, furans and pyrans were the most important sensory active compounds. Their amounts increased by the addition of sugars to semolina; the mixture of semolina with glucose was particularly rich in active compounds. The formation of pyrazines was more enhanced by the addition of fructose than of other sugars. Maltol, butyrolactone and acetic acid were present in large amounts. Even if sensory characteristics were improved by addition of sugars to semolina, the difference was not very pronounced.

2011 ◽  
Vol 20 (No. 6) ◽  
pp. 229-236 ◽  
Author(s):  
J. Pokorný ◽  
A. Farouk Mansour ◽  
F. Pudil ◽  
V. Janda

Mixtures of wheat semolina, 5% glucose and 0–30% defatted soybean flour were used for the preparation of extruded samples using a pilot plant single screw extruder, maximum temperature being 140°C. The browning reactions were only moderate, the intensities of the trichromatic a* coordinate increased, and some changes were observed in chroma and the odour difference ΔE*. The sensory acceptability improved by increasing the content of soybean flour, the odour intensity increased, and some changes were observed in the sensory profile. Volatile substances were isolated using a SPME procedure, and the volatiles were separated using a Fisons GLC 8000 apparatus equipped with a mass spectrometer. Among the flavour active volatiles, pyrazines were the most prominent class of compounds, especially methyl and ethyl substituted derivatives. Pyrrole and furan substituted pyrazines were found only in small amounts because of the low extrusion temperature. Other furan and pyrrole derivatives had a lesser effect on flavour because of their relatively low amounts. Aldehydes, fatty acids, ketones, and other aliphatic derivatives contributed only a little to the resulting flavour. Compared to the mixtures of semolina and glucose only, the additions of defatted soybean flour moderately increased the number of substituted pyrazines detected in the extruded mixtures but increased substantially the pyrazine fraction in the total peak area. Among furan derivatives, 2-furancarboxaldehyde, 2-furanmethanol and 5-methyl-2-furyl alcohol belonged to the most prominent derivatives. Among other compounds, acetic acid, butyrolactone and maltol should be mentioned.  


2021 ◽  
pp. 108201322110037
Author(s):  
G Brunda ◽  
Urs Kavyashree ◽  
Shilpa S Shetty ◽  
Kirti Sharma

Pomegranate juice is popular due to its unique health benefits, sensory characteristics and also a good source of bioactive compounds. Comparative study on processing effect of Not from Concentrate (NFC) and Reconstituted from concentrate (RFC) pomegranate juice on the nutritional and sensory characteristics of ‘Ganesh’ variant was conducted. Results showed that not much differences observed in parameters like pH, acidity, essential elements, protein, total sugars and polyphenol content between NFC and RFC. As per the study NFC had a better antioxidant activity with intracellular ROS inhibition of 11% higher with significant ( p < 0.05) than RFC in HepG2 cell lines. Total anthocyanin content was significantly different ( p < 0.05) in NFC (428.05 mg/l) compared to 326.74 mg/l in RFC expressed as cyanidin-3-glucoside. Iron uptake was 40 units (µg/mg protein) higher in NFC than RFC ( p < 0.05) in HepG2 cells. Sensory flavor profile showed NFC having significant differences with respect to characteristic pomegranate freshness, fruitiness, sweetness and astringency mouthfeel. RFC had higher sweetish and cooked flavor with additional vegetable like notes of beet and carrot. Based on the data better antioxidant activity, iron bioavailability, anthocyanin content and sensory attributes were captured in pomegranate NFC juices over RFC juices.


Author(s):  
Nardis NKOUDOU ZE ◽  
Marie-Joseph MEDZEME ENGAMA ◽  
Jean Justin ESSIA NGANG

Aim: the aim of this study was to determine sensory profile, through the use of just-about-right (JAR) scales and penalty analysis, of Bobolo and Chikwangue from the cassava roots fermented with previously cassava-fermented chips powder (PCFCP). Furthermore, retting time, cyanide content and pasting properties of retted roots were evaluated. Methods: for that, two samples of Bobolo and Chikwangue obtained from two cassava retting methods were studied: a control made from the retting without PCFCP and a product made from retting with PCFCP. Results: retting time was carried out in 48 hours less with PCFCP and 60% of cyanide reduction more than control. No major modifications occurs in pasting properties of paste fermented with PCFCP. The sensory analysis indicated high levels of acceptability for products made from retting with PCFCP. The penalty analysis showed that attributes “too sour” and “too much fermented odor” affected the acceptability of the Bobolo from retting without PCFCP significantly. Conclusion: fermentation of cassava through the use of PCFCP is suitable to improvement of sensory characteristics of fermented cassava by-products.


2018 ◽  
Vol 38 ◽  
pp. 03020 ◽  
Author(s):  
Zheng Si ◽  
Qian Zhang ◽  
Ling Zhi Huang ◽  
Dan Yang

Most existing temperature field calculation programs have relative defects. In the present paper, based on merits of ANSYS platform, a temperature field calculation program of mass concrete structure is developed and demonstrated. According to actual pouring progress and thermodynamic parameters, a roller-compacted concrete dam is simulated. The difference of maximum temperature between calculated and measured values of measuring points is less than 1.8°C. Furthermore, the relative difference is -5%–5%. This result shows that the calculation program developed based on ANSYS platform can simulate and calculate the temperature field of mass concrete structure.


2009 ◽  
Vol 81 (1) ◽  
pp. 143-149 ◽  
Author(s):  
Carlos A.L. Carvalho ◽  
Geni S. Sodré ◽  
Antonio A.O. Fonseca ◽  
Rogério M.O. Alves ◽  
Bruno A. Souza ◽  
...  

This study was conducted to evaluate the effect of a dehumidification process on the physicochemical and sensory characteristics of stingless-bee honey. Melipona scutellaris and M. quadrifasciata honey samples were submitted to a dehumidification process and to physicochemical (reducing sugars, apparent sucrose, moisture, diastatic activity, hydroxymethylfurfural, ash, pH, acidity, and electric conductivity) and sensory evaluations (fluidity, color, aroma, crystallization,flavor,and acceptability). The results indicated that the dehumidification process does not interfere with honey quality and acceptability.


CytoJournal ◽  
2015 ◽  
Vol 12 ◽  
pp. 23 ◽  
Author(s):  
Nora K. Frisch ◽  
Yasin Ahmed ◽  
Seema Sethi ◽  
Daniel Neill ◽  
Tatyana Kalinicheva ◽  
...  

Background: ThinPrep® (TP) cervical cytology, as a liquid-based method, has many benefits but also a relatively high unsatisfactory rate due to debris/lubricant contamination and the presence of blood. These contaminants clog the TP filter and prevent the deposition of adequate diagnostic cells on the slide. An acetic acid wash (AAW) protocol is often used to lyse red blood cells, before preparing the TP slides. Design: From 23,291 TP cervical cytology specimens over a 4-month period, 2739 underwent AAW protocol due to initial unsatisfactory smear (UNS) with scant cellularity due to blood or being grossly bloody. Randomly selected 2739 cervical cytology specimens which did not undergo AAW from the same time period formed the control (non-AAW) group. Cytopathologic interpretations of AAW and non-AAW groups were compared using the Chi-square test. Results: About 94.2% of the 2739 cases which underwent AAW were subsequently satisfactory for evaluation with interpretations of atypical squamous cells of undetermined significance (ASCUS) 4.9% (135), low-grade squamous intraepithelial lesions (LSIL) 3.7% (102), and high-grade squamous intraepithelial lesions (HSIL) 1% (28). From the 2739 control cases, 96.3% were satisfactory with ASCUS 5.5% (151), LSIL 5.1% (139), and HSIL 0.7% (19). The prevalence of ASCUS interpretations was similar (P = 0.33). Although there were 32% more HSIL interpretations in the AAW group (28 in AAW vs. 19 in non-AAW), the difference was statistically insignificant (P = 0.18). AAW category; however, had significantly fewer LSIL interpretations (P = 0.02). The percentage of UNS cases remained higher in the AAW group with statistical significance (P < 0.01). Conclusions: While AAW had a significantly higher percent of UNS interpretations, the protocol was effective in rescuing 94.2% of specimens which otherwise may have been reported unsatisfactory. This improved patient care by avoiding a repeat test. The prevalence of ASCUS and HSIL interpretations between AAW and non-AAW groups were comparable. Though not statistically significant, HSIL interpretations were relatively higher in the AAW group. LSIL interpretations showed lower prevalence in AAW group.


2019 ◽  
Vol 57 (4) ◽  
pp. 503-512
Author(s):  
Karolina Brkić Bubola ◽  
Marina Lukić ◽  
Igor Lukić ◽  
Olivera Koprivnjak

This study investigates the effect of industrial scale filtration of fresh monovarietal virgin olive oil from Buža and Istarska bjelica cultivars on their volatiles, total phenols and sensory characteristics, and compares the oil samples clarified by filtration with those clarified by natural sedimentation/decantation after six months of storage. Filtration had a different effect on volatiles from the oil samples obtained from different cultivars. In the oil from Buža cultivar immediately after filtration only the amount of (Z)-2-pentenol slightly increased, but in Istarska bjelica the oil filtration affected eight compounds (the amount of hexanal, (E)-2-pentenal, (Z)-3-hexenal, (Z)-2-pentenol and (Z)-3-hexen-1-ol increased, while of hexyl acetate, (E)-2-penten-1-ol and (E)-2-hexen-1-ol decreased). In fresh filtered oil from Buža cultivar a slight decrease of total phenols was observed, while in those from Istarska bjelica the decrease was sharp, causing a decrease in the pungency and bitterness. Sedimentation/decantation had advantages over oil filtration of both cultivars, due to improved effect on the preservation of the sensory profile and the level of total phenols. Tentative aroma profiles based on odorant series obtained from the odour activity values were compared to the actual olive oil sensory profiles. These results could have a high level of applications in the olive oil industry for the optimization of the technology for obtaining monovarietal virgin olive oil with preserved specific and typical sensory characteristics, but also may serve experts to choose an appropriate virgin olive oil clarification method prior to analysis of volatile compounds.


2019 ◽  
Vol 8 (5) ◽  
pp. 372-379 ◽  
Author(s):  
Laila Makouki ◽  
Meriem Tarbaoui ◽  
Samia Glissi ◽  
Said Mansouri ◽  
Hassan Hannache ◽  
...  

The present article aims to optimize the decarbonization of Timahdit oil shale layer Y by removing carbonates from the raw rock using acetic acid. The response surface methodology “central composite design (CCD)” has been used as a method of optimization to study the 3 factors of the process. The factors studied are the concentration of the acid, the processing time, and the ratio (liquid/solid). The optimal conditions with 68.17% of residue rate are obtained with 2 mol/l as concentration, 120 min as a time of treatment and 10.02 for the ratio.The raw (Y) and optimized materials (YO) were characterized by Scanning Electron Microscopy (SEM), X-ray fluorescence (XRF) and X-ray diffraction (XRD). The results showed that the acetic acid used to remove carbonates affects the chemical composition and the texture evolution of the residues.


2014 ◽  
Vol 1044-1045 ◽  
pp. 215-218
Author(s):  
Xian Huan Qiu ◽  
Hai Yu ◽  
Peng Fei Deng

In the presence of acetic acid, the effects of pH, processing time, addition of Fe2+ and H2O2 on dye wastewater treatment were studied. Experimental results showed that in the presence of acetic acid, when the pH value was 4, the processing time was 30.0min, addition of ferrous sulfate was 4.8g/L, and addition of hydrogen peroxide was 56mL/L, the treatment effect was the best, COD removal rate reached 51.0%. Further studied of the effect of the presence of acetic acid on Fenton’s oxidation of dye wastewater, the results showed that without of acetic acid, the COD removal rate was higher than that with acetic acid. And the effect of Fenton's reagent on oxidation of dye substances was interfered by the presence of acetic acid.


2021 ◽  
Author(s):  
Guangte Xiang ◽  
Yurui Hu ◽  
Sheng Zeng ◽  
Jianfeng Shi ◽  
Jinyang Zheng

Abstract Electrofusion (EF) welding is one of the most common connection methods for polyethylene (PE) pipe, as well as thermoplastic pipe and reinforced composite pipe. Conventional EF welding generally adopts constant-voltage welding mode. The welding machine outputs a constant welding voltage to heat the resistance wire within specific welding time. In our previous study, intelligent welding machine was designed to ensure the quality of the EF joint, based on the study of the temperature field in EF joint. In this paper, three experiments were used to show the difference between the intelligent welding machine and traditional welding machine. The intelligent welding machine can actively adjust the welding parameters to ensure the quality of EF joint even it was given the wrong welding voltage and welding time. Compared with the traditional welding machine, the intelligent welding machine can automatically control the maximum temperature and the depth of melting region in EF joint during the welding process, and this method applies for EF joints with various diameters or design welding parameters.


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