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Volume 24 (2020): Edition 1 (June 2020)

Volume 23 (2019): Edition 2 (December 2019)

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Volume 22 (2018): Edition 2 (December 2018)

Volume 22 (2018): Edition 1 (August 2018)

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Détails du magazine
Format
Magazine
eISSN
2344-150X
Première publication
30 Jul 2013
Période de publication
2 fois par an
Langues
Anglais

Chercher

Volume 24 (2020): Edition 2 (December 2020)

Détails du magazine
Format
Magazine
eISSN
2344-150X
Première publication
30 Jul 2013
Période de publication
2 fois par an
Langues
Anglais

Chercher

13 Articles
access type Accès libre

Impact of Ozonation Process on the Content of Bioactive Compounds with Antioxidant Properties in Scots Pine (Pinus sylvestris L.) Shoots as Well as Yield and Composition of Essential Oils

Publié en ligne: 24 Dec 2020
Pages: 146 - 155

Résumé

Abstract

This study examined the impact of the ozonation procedure on the content of bioactive compounds in young shoots of Pinus sylvestris L. as well as on the yield and the composition of the essential oils and volatile fraction. The ozonation process consisted of exposure of the raw material during 5, 15 and 30 min to the ozone gas with the concentration of 10 and 100 ppm, and then it was stored for 24 hours. In the ozonated pine shoots, the content of vitamin C overall content of polyphenol content and antioxidant potential were determined. It was found that the investigated parameters increased as a result of the utilized procedure. The observed increase in the content of tested bioactive compounds was dependent on exposition time and was found to be highest for ozonated material for 15 min with ozone gas at a concentration of 10 ppm. As a result of the ozonation procedure the content of polyphenolic compounds and vitamin C content increased. Whereas it, did not have a significant effect on composition of the obtained essential oils. It was found that ozone is an effective elicitor, which allows increasing the content of bioactive compounds in pine shoots.

Mots clés

  • scots pine
  • ozonation
  • antioxidant activity
  • polyphenols
  • essential oils
  • HS-SPME
access type Accès libre

Utilization of Ozone for the Improvement of Mentha piperita L. Quality by Reduction of Microbial Load and Impact of the Process on the Herb Properties

Publié en ligne: 24 Dec 2020
Pages: 156 - 164

Résumé

Abstract

Herbs can be contaminated with microorganisms, which affects their quality while increasing the risk of food poisoning. Thus, there is a need for efficient decontamination techniques. In this study, the microbial load was reduced in peppermint herb (Mentha piperita L.) exposed to ozone at 10 ppm for 60 minutes. The quality of the ozonated herb was assessed by the determination of microbial load and essential oils content. Total microbial content was reduced by 4 log cfu g−1 of the microorganisms whereas the contamination with molds was reduced from 10.07 log cfu g−1 of the microorganisms to zero. Moreover, sensory evaluation of the herb aroma was conducted. These characteristics were not significantly affected by the treatment. Therefore, ozone can be used to improve the peppermint herb quality by reduction of the microbial contamination of peppermint herb while having no adverse effect on the herb aroma.

Mots clés

  • quality management
  • ozone
  • herbs
  • essential oil content
  • microbial load
access type Accès libre

Exploring in Vitro Antioxidant Activity and Physicochemical Properties of Selected Under-Exploited Tropical Fruits

Publié en ligne: 24 Dec 2020
Pages: 165 - 174

Résumé

Abstract

Dacryodes edulis (DE), Dalium guineensis (DG), Spondias mombin (SM) and Irvingia gabonensis (IG) as notable underexploited tropical wild fruits in Nigeria, were evaluated for quality characteristics, phenolic contents and in-vitro antioxidant activity. pH of the fruits ranked thus DE > IG > DG > SM and the reverse order was true for acidity. IG exhibited highest obrix, vitamin C and total sugar content. DE had no detectable reducing sugar compared to 18.84% in IG. Total phenol and flavonoid contents followed the same pattern with DG as the highest (1796.89 ± 71.1 and 860.64 ± 3.7 mg/100g) and IG as the lowest (454.23 ± 13.9 and 304.98 ± 7.5 mg/100g), respectively. Regarding antioxidant activities, SM was significant for ABTS•, DE and IG were similar in FRAP assay, while all the fruits were effective DPPH• radical scavengers. Generally, the fruits demonstrate high food application potentials with possible health benefits if consumed adequately.

Mots clés

  • Underexploited tropical fruits
  • quality parameters
  • phenolic contents
  • in vitro antioxidant assays
access type Accès libre

Changes in the Quality of Old Apple Cultivars After Freeze-Drying

Publié en ligne: 24 Dec 2020
Pages: 175 - 185

Résumé

Abstract

There are several thousand different cultivars of apple trees but only a limited number are cultivated on an industrial scale. Old cultivars can be useful, for example, in the processing industry due to their different composition. In many cases, they have higher organic acid content. The content of mineral components, colour, and polyphenols in the fruit of 7 old apple tree cultivars, growing in the Wolinski National Park, was studied. The changes that occurred in the fruit after freeze-drying were also evaluated. The trees from which the fruit was picked for analysis, despite the lack of chemical protection, were fruiting and the apples had only a few symptoms of damage caused by pests or diseases. The fruit was characterised by a high soluble solids content (14.4-16.4%), in which sugars and especially fructose dominated. The number of organic acids varied greatly and ranged from 0.27 (Oberlander Himbeerapfel) g to 1.07 g/100 g (Winter Goldparmane). The content of polyphenols in fresh apples ranged from 186 mg (Horneburger Pfannkuchenapfel) to 354 mg/100 g (Winter Goldparmane) and increased after freeze-drying from 666 mg (Weisser Winterkalvill) to 1486 mg/100 g (Winter Goldparmane). The dominant group of polyphenolic compounds was phenolic acid. The freeze-drying process caused unfavourable changes in the colour of the pulp. The fruits of Oberlander Himbeerapfel cultivar were most susceptible to these changes. However, the least darkened fruit of Horneburger Pfannkuchenapfel.

Mots clés

  • polyphenolic compounds
  • colour changes
  • pathogens contamination
access type Accès libre

Optimization of Peroxidase Activity of Turnip (Brassica rapa) Using Response Surface Methodology

Publié en ligne: 24 Dec 2020
Pages: 186 - 194

Résumé

Abstract

The present study is focused on the determination of optimized activity conditions of peroxidase (POD) of turnip (Brassica rapa). The enzyme is extracted from turnip with 0.5M Na2HPO4 (pH7.0). Peroxidase activity is evaluated by monitoring the oxidation of guaiacol to tetraguaiacol in the presence of hydrogen peroxide (H2O2). Before the optimization of peroxidase activity from a turnip by response surface methodology (RSM), a preliminary step is conducted for each studied parameter (pH, temperature, and NaCl concentration). Further, RSM following Box-Behnken design is used in order to refine the optimization of the conditions. Response surface analysis showed that parameter values with the highest peroxidase activity are 5.9, 29.8°C, and 1.07M for pH, temperature, and NaCl, respectively. Under these experimental conditions, peroxidase activity is found to be 4027.25U/mg. The obtained experimental value agrees with that of the calculated one, indicating the pertinence of the developed model for the optimization of peroxidase activity.

Mots clés

  • Peroxidase activity
  • turnip
  • optimization
  • response surface methodology
access type Accès libre

Nutritional, Antinutritional and Phenolic Properties of Lima Bean (Phaseolus lunatus) Accessions: Underutilized Legume in Ethiopia

Publié en ligne: 24 Dec 2020
Pages: 195 - 204

Résumé

Abstract

The study was aimed to evaluate nutritional compositions, anti- nutritional factors and antioxidant properties of lima bean accessions grown in East Shoa Zone, Ethiopia. The lima bean accessions were studied and compared for their nutritional composition, anti-nutritional factors and antioxidant properties. The result showed that lima bean accessions were good source of vital nutrients when compared to the commonly consumed legumes in Ethiopia. Particularly, lima bean accessions “LB8510” rich in crude protein whereas accession “LB85CH2” rich in crude fiber, total ash and iron and can be implemented for breeding, new product development and used as alternative source of nutrient rich to mitigate malnutrition prevalent in Ethiopia. Therefore, increasing its consumption, cultivation and promotion should be encouraged.

Mots clés

  • Lima bean
  • Accession
  • Nutritional
  • Anti-nutritional and Antioxidants
access type Accès libre

Biscuits from Fermented Roasted Buckwheat Flour - Phenolics Profile and Bioaccessible Angiotensin Converting Enzyme Inhibitory Activity

Publié en ligne: 24 Dec 2020
Pages: 205 - 214

Résumé

Abstract

The bioaccessible angiotensin converting enzyme (ACE) inhibitory activity of biscuits formulated from roasted common buckwheat flour after fermentation by select bacteria was studied. The same content of total phenolic compounds was found in fermented flour and in biscuits obtained from them. Generally, fermentation of flour did not changes the ACE inhibitory activity, whereas baking process significantly increased the ACE inhibitory activity of examined products. The potential bioaccessible ACE inhibitory activity from biscuits was very high. Phenolic acids such as protocatechuic, vanillic and syringic acids as well as flavonoids: kaempferol and epicatechin in the digested buckwheat biscuits have the highest impact on ACE inhibitory activity. A high significant correlations were found between IC50 and total phenolic compounds of fermented flours, biscuits before and after digestion. The data obtained in this study closely associates phenolic compounds with ACE inhibitory activity.

Mots clés

  • buckwheat
  • roasting
  • fermentation
  • baking
  • digestion
  • ACE inhibition
access type Accès libre

Nutritional Properties of Sakada Produced from Blends of Cassava and African Yam Bean Flours

Publié en ligne: 24 Dec 2020
Pages: 215 - 222

Résumé

Abstract

This study investigated the effect of African yam bean flour (AYF) inclusion on the quality of sakada. Fermented cassava mash (FCM) and AYF were blended at ratios (% w/w) 100:0 (control), 90:10, 80:20, 70:30, and 60:40. Sakada was produced using the blends, and its nutritional and sensory properties were determined. Protein, fat, crude fibre, P, Ca, phytate, and oxalate contents of sakada increased (p < 0.05) with increasing AYF level, while moisture, carbohydrate, and cyanide decreased. The incorporation of 20% AYF in sakada resulted in a significant amount (> 4.0 g/100g protein) of arginine, leucine, isoleucine, and phenylalanine. Sensory properties of sakada that contained ≤ 20% AYF compared favourably with sakada produced using 100% FCM. This study showed that the nutritional quality of sakada improved following AYF incorporation.

Mots clés

  • African yam bean
  • cassava mash
  • enrichment
  • snack
access type Accès libre

The Use of Non-Saccharomyces Yeast and Enzymes in Beer Production

Publié en ligne: 24 Dec 2020
Pages: 223 - 246

Résumé

Abstract

The objective of this paper was to test the potential of selected non-Saccharomyces strains for beer production, by using Saccharomyces cerevisiae as a control sample. For some of variants brewing enzymes were added to wort to increase the content of fermentable sugars. The non-Saccharomyces yeasts differed in the fermentation process rate. The basic beer physiochemical parameters were assessed, including: alcohol content, extract, free amino nitrogen, sugars, acidity, colour, and the profile of volatile compounds and metal ions. The use of enzymes caused an increase in alcohol and fusel alcohols concentration in beers obtained. Total acidity, free amine nitrogen content, colour and sugar content indicated that the tested non-Saccharomyces yeast allowed obtaining beers with the proper analytical parameters.

Mots clés

  • beer
  • non- yeast
  • enzymes
  • fermentation
  • volatile compounds
access type Accès libre

Mathematical Modelling and Numerical Simulation of Mass Transfer During Deep-Fat Frying of Plantain (Musa paradisiacal AAB) Chips (ipekere)

Publié en ligne: 24 Dec 2020
Pages: 247 - 256

Résumé

Abstract

This study developed a mathematical model following the fundamental principles of mass transfer for the simulation of the oil and moisture content change during the Deep-Fat Frying of plantain (ipekere) chip. The explicit Finite Difference Technique (FDT) was used to conduct a numerical solution to the consequential governing equation (partial differential equation) that was used to describe the mass transfer rate during the process. Computer codes that were computed in MATLAB were used for the implementation of FDT at diverse frying conditions. Samples of the plantain were cut into portions of 2 mm thickness, and these sliced portions were fried at separate frying oil temperatures (170, 180 and 190°C) between 0.5 and 4 minutes. The experimental data and the predicted outcomes were compared for the validation of the model, and the juxtaposition revealed a plausible agreement. The predicted values and the experimental values of oil and moisture transfer models produced correlation coefficients that range from 0.96 to 0.99 and 0.94 to 0.99, respectively. The predicted outcomes could be utilized for the control and design of the DFF.

Mots clés

  • mass transfer
  • moisture loss
  • oil uptake
  • frying
  • plantain
access type Accès libre

Mathematical Modelling of the Mechanical Properties of Four Varieties of Brine Pickles Using Neural Networks

Publié en ligne: 24 Dec 2020
Pages: 257 - 268

Résumé

Abstract

The study assesses the impact of selected fruit properties and the souring process parameters on the mechanical properties of four varieties of field cucumbers (Śremianin, Śremski, Polan and Izyd) harvested from 2014 to 2016. The analyses focused on the changes in the values of the puncture strength parameters of the peel and the mesocarp, the deformation from the moment of puncture and the energy needed to puncture the peel and the mesocarp of the selected cucumber varieties relative to the year of harvest, fruit size, type of brine, puncture location and souring time. Neural networks were used to model the relationships studied. Sensitivity analysis of the obtained models showed that the length fraction had the greatest impact on the puncture strength and the energy needed to puncture the peel and the mesocarp. On the other hand, deformation was most affected by the souring time and the brine composition.

Mots clés

  • cucumber
  • puncture strength
  • neural modelling
  • sensitivity analysis
access type Accès libre

Characteristics of Technological Properties of Grain and Flour from Ancient Varieties of Wheat (Einkorn, Emmer and Spelt)

Publié en ligne: 24 Dec 2020
Pages: 269 - 278

Résumé

Abstract

The study presents assessment of commodity characteristics of grains from ancient varieties of wheat (einkorn, emmer and spelt) in comparison to grains of the conventional wheat cultivar Arkadia. The findings related to the grain of einkorn and emmer were very similar, and far worse than those related to spelt grain; the latter were found with better ratings, sometimes even in comparison to the conventional wheat grain (e.g. the highest mass-weight density). Similar relationships were observed between the flours produced by milling the grains. Analysis of the indirect baking quality indicators showed that flours from einkorn and emmer can effectively be used for baking purposes, however they present low technological value. The flour from emmer wheat was found to be the poorest, which was confirmed e.g. by the low gluten number, gluten index, Zeleny’s index, and high gluten spreadability. Spelt flour was found to present moderate technological value. Based on the results it can be concluded that by using adequate modification in the process of dough kneading and fermentation it will be possible to produce high quality baked goods from ancient wheat grains.

Mots clés

  • einkorn wheat
  • emmer wheat
  • spelt
  • assessment of grain as a commodity
  • baking properties of flour
access type Accès libre

Effect of Tytanit® on the Physiological Activity of Wild Strawberry (Fragaria vesca L.) Grown in Salinity Conditions

Publié en ligne: 24 Dec 2020
Pages: 279 - 288

Résumé

Abstract

Progressive global warming and decreasing freshwater resources are forcing to look for alternative solutions in plants cultivation. The use of saltwater and cultivation in saline areas becomes increasingly common. Wild strawberry is a rich source of antioxidant compounds beneficial for human health. The aim of the study was to investigate the effect of Tytanit® on the physiological activity of wild strawberry grown under different salinity levels (32.5, 50 and 100 mM L−1 NaCl). Assimilatory pigments content, free proline concentration, chlorophyll fluorescence and relative water content were measured at two phenological phases BBCH 15 and 60. Results analysis revealed that the applicability of Tytanit® to mitigate physiological stress in wild strawberry caused by salinity did not produce the desired effect.

Mots clés

  • chlorophyll-a
  • chlorophyll-b
  • carotenoids
  • proline
  • chlorophyll fluorescence
  • water balance
13 Articles
access type Accès libre

Impact of Ozonation Process on the Content of Bioactive Compounds with Antioxidant Properties in Scots Pine (Pinus sylvestris L.) Shoots as Well as Yield and Composition of Essential Oils

Publié en ligne: 24 Dec 2020
Pages: 146 - 155

Résumé

Abstract

This study examined the impact of the ozonation procedure on the content of bioactive compounds in young shoots of Pinus sylvestris L. as well as on the yield and the composition of the essential oils and volatile fraction. The ozonation process consisted of exposure of the raw material during 5, 15 and 30 min to the ozone gas with the concentration of 10 and 100 ppm, and then it was stored for 24 hours. In the ozonated pine shoots, the content of vitamin C overall content of polyphenol content and antioxidant potential were determined. It was found that the investigated parameters increased as a result of the utilized procedure. The observed increase in the content of tested bioactive compounds was dependent on exposition time and was found to be highest for ozonated material for 15 min with ozone gas at a concentration of 10 ppm. As a result of the ozonation procedure the content of polyphenolic compounds and vitamin C content increased. Whereas it, did not have a significant effect on composition of the obtained essential oils. It was found that ozone is an effective elicitor, which allows increasing the content of bioactive compounds in pine shoots.

Mots clés

  • scots pine
  • ozonation
  • antioxidant activity
  • polyphenols
  • essential oils
  • HS-SPME
access type Accès libre

Utilization of Ozone for the Improvement of Mentha piperita L. Quality by Reduction of Microbial Load and Impact of the Process on the Herb Properties

Publié en ligne: 24 Dec 2020
Pages: 156 - 164

Résumé

Abstract

Herbs can be contaminated with microorganisms, which affects their quality while increasing the risk of food poisoning. Thus, there is a need for efficient decontamination techniques. In this study, the microbial load was reduced in peppermint herb (Mentha piperita L.) exposed to ozone at 10 ppm for 60 minutes. The quality of the ozonated herb was assessed by the determination of microbial load and essential oils content. Total microbial content was reduced by 4 log cfu g−1 of the microorganisms whereas the contamination with molds was reduced from 10.07 log cfu g−1 of the microorganisms to zero. Moreover, sensory evaluation of the herb aroma was conducted. These characteristics were not significantly affected by the treatment. Therefore, ozone can be used to improve the peppermint herb quality by reduction of the microbial contamination of peppermint herb while having no adverse effect on the herb aroma.

Mots clés

  • quality management
  • ozone
  • herbs
  • essential oil content
  • microbial load
access type Accès libre

Exploring in Vitro Antioxidant Activity and Physicochemical Properties of Selected Under-Exploited Tropical Fruits

Publié en ligne: 24 Dec 2020
Pages: 165 - 174

Résumé

Abstract

Dacryodes edulis (DE), Dalium guineensis (DG), Spondias mombin (SM) and Irvingia gabonensis (IG) as notable underexploited tropical wild fruits in Nigeria, were evaluated for quality characteristics, phenolic contents and in-vitro antioxidant activity. pH of the fruits ranked thus DE > IG > DG > SM and the reverse order was true for acidity. IG exhibited highest obrix, vitamin C and total sugar content. DE had no detectable reducing sugar compared to 18.84% in IG. Total phenol and flavonoid contents followed the same pattern with DG as the highest (1796.89 ± 71.1 and 860.64 ± 3.7 mg/100g) and IG as the lowest (454.23 ± 13.9 and 304.98 ± 7.5 mg/100g), respectively. Regarding antioxidant activities, SM was significant for ABTS•, DE and IG were similar in FRAP assay, while all the fruits were effective DPPH• radical scavengers. Generally, the fruits demonstrate high food application potentials with possible health benefits if consumed adequately.

Mots clés

  • Underexploited tropical fruits
  • quality parameters
  • phenolic contents
  • in vitro antioxidant assays
access type Accès libre

Changes in the Quality of Old Apple Cultivars After Freeze-Drying

Publié en ligne: 24 Dec 2020
Pages: 175 - 185

Résumé

Abstract

There are several thousand different cultivars of apple trees but only a limited number are cultivated on an industrial scale. Old cultivars can be useful, for example, in the processing industry due to their different composition. In many cases, they have higher organic acid content. The content of mineral components, colour, and polyphenols in the fruit of 7 old apple tree cultivars, growing in the Wolinski National Park, was studied. The changes that occurred in the fruit after freeze-drying were also evaluated. The trees from which the fruit was picked for analysis, despite the lack of chemical protection, were fruiting and the apples had only a few symptoms of damage caused by pests or diseases. The fruit was characterised by a high soluble solids content (14.4-16.4%), in which sugars and especially fructose dominated. The number of organic acids varied greatly and ranged from 0.27 (Oberlander Himbeerapfel) g to 1.07 g/100 g (Winter Goldparmane). The content of polyphenols in fresh apples ranged from 186 mg (Horneburger Pfannkuchenapfel) to 354 mg/100 g (Winter Goldparmane) and increased after freeze-drying from 666 mg (Weisser Winterkalvill) to 1486 mg/100 g (Winter Goldparmane). The dominant group of polyphenolic compounds was phenolic acid. The freeze-drying process caused unfavourable changes in the colour of the pulp. The fruits of Oberlander Himbeerapfel cultivar were most susceptible to these changes. However, the least darkened fruit of Horneburger Pfannkuchenapfel.

Mots clés

  • polyphenolic compounds
  • colour changes
  • pathogens contamination
access type Accès libre

Optimization of Peroxidase Activity of Turnip (Brassica rapa) Using Response Surface Methodology

Publié en ligne: 24 Dec 2020
Pages: 186 - 194

Résumé

Abstract

The present study is focused on the determination of optimized activity conditions of peroxidase (POD) of turnip (Brassica rapa). The enzyme is extracted from turnip with 0.5M Na2HPO4 (pH7.0). Peroxidase activity is evaluated by monitoring the oxidation of guaiacol to tetraguaiacol in the presence of hydrogen peroxide (H2O2). Before the optimization of peroxidase activity from a turnip by response surface methodology (RSM), a preliminary step is conducted for each studied parameter (pH, temperature, and NaCl concentration). Further, RSM following Box-Behnken design is used in order to refine the optimization of the conditions. Response surface analysis showed that parameter values with the highest peroxidase activity are 5.9, 29.8°C, and 1.07M for pH, temperature, and NaCl, respectively. Under these experimental conditions, peroxidase activity is found to be 4027.25U/mg. The obtained experimental value agrees with that of the calculated one, indicating the pertinence of the developed model for the optimization of peroxidase activity.

Mots clés

  • Peroxidase activity
  • turnip
  • optimization
  • response surface methodology
access type Accès libre

Nutritional, Antinutritional and Phenolic Properties of Lima Bean (Phaseolus lunatus) Accessions: Underutilized Legume in Ethiopia

Publié en ligne: 24 Dec 2020
Pages: 195 - 204

Résumé

Abstract

The study was aimed to evaluate nutritional compositions, anti- nutritional factors and antioxidant properties of lima bean accessions grown in East Shoa Zone, Ethiopia. The lima bean accessions were studied and compared for their nutritional composition, anti-nutritional factors and antioxidant properties. The result showed that lima bean accessions were good source of vital nutrients when compared to the commonly consumed legumes in Ethiopia. Particularly, lima bean accessions “LB8510” rich in crude protein whereas accession “LB85CH2” rich in crude fiber, total ash and iron and can be implemented for breeding, new product development and used as alternative source of nutrient rich to mitigate malnutrition prevalent in Ethiopia. Therefore, increasing its consumption, cultivation and promotion should be encouraged.

Mots clés

  • Lima bean
  • Accession
  • Nutritional
  • Anti-nutritional and Antioxidants
access type Accès libre

Biscuits from Fermented Roasted Buckwheat Flour - Phenolics Profile and Bioaccessible Angiotensin Converting Enzyme Inhibitory Activity

Publié en ligne: 24 Dec 2020
Pages: 205 - 214

Résumé

Abstract

The bioaccessible angiotensin converting enzyme (ACE) inhibitory activity of biscuits formulated from roasted common buckwheat flour after fermentation by select bacteria was studied. The same content of total phenolic compounds was found in fermented flour and in biscuits obtained from them. Generally, fermentation of flour did not changes the ACE inhibitory activity, whereas baking process significantly increased the ACE inhibitory activity of examined products. The potential bioaccessible ACE inhibitory activity from biscuits was very high. Phenolic acids such as protocatechuic, vanillic and syringic acids as well as flavonoids: kaempferol and epicatechin in the digested buckwheat biscuits have the highest impact on ACE inhibitory activity. A high significant correlations were found between IC50 and total phenolic compounds of fermented flours, biscuits before and after digestion. The data obtained in this study closely associates phenolic compounds with ACE inhibitory activity.

Mots clés

  • buckwheat
  • roasting
  • fermentation
  • baking
  • digestion
  • ACE inhibition
access type Accès libre

Nutritional Properties of Sakada Produced from Blends of Cassava and African Yam Bean Flours

Publié en ligne: 24 Dec 2020
Pages: 215 - 222

Résumé

Abstract

This study investigated the effect of African yam bean flour (AYF) inclusion on the quality of sakada. Fermented cassava mash (FCM) and AYF were blended at ratios (% w/w) 100:0 (control), 90:10, 80:20, 70:30, and 60:40. Sakada was produced using the blends, and its nutritional and sensory properties were determined. Protein, fat, crude fibre, P, Ca, phytate, and oxalate contents of sakada increased (p < 0.05) with increasing AYF level, while moisture, carbohydrate, and cyanide decreased. The incorporation of 20% AYF in sakada resulted in a significant amount (> 4.0 g/100g protein) of arginine, leucine, isoleucine, and phenylalanine. Sensory properties of sakada that contained ≤ 20% AYF compared favourably with sakada produced using 100% FCM. This study showed that the nutritional quality of sakada improved following AYF incorporation.

Mots clés

  • African yam bean
  • cassava mash
  • enrichment
  • snack
access type Accès libre

The Use of Non-Saccharomyces Yeast and Enzymes in Beer Production

Publié en ligne: 24 Dec 2020
Pages: 223 - 246

Résumé

Abstract

The objective of this paper was to test the potential of selected non-Saccharomyces strains for beer production, by using Saccharomyces cerevisiae as a control sample. For some of variants brewing enzymes were added to wort to increase the content of fermentable sugars. The non-Saccharomyces yeasts differed in the fermentation process rate. The basic beer physiochemical parameters were assessed, including: alcohol content, extract, free amino nitrogen, sugars, acidity, colour, and the profile of volatile compounds and metal ions. The use of enzymes caused an increase in alcohol and fusel alcohols concentration in beers obtained. Total acidity, free amine nitrogen content, colour and sugar content indicated that the tested non-Saccharomyces yeast allowed obtaining beers with the proper analytical parameters.

Mots clés

  • beer
  • non- yeast
  • enzymes
  • fermentation
  • volatile compounds
access type Accès libre

Mathematical Modelling and Numerical Simulation of Mass Transfer During Deep-Fat Frying of Plantain (Musa paradisiacal AAB) Chips (ipekere)

Publié en ligne: 24 Dec 2020
Pages: 247 - 256

Résumé

Abstract

This study developed a mathematical model following the fundamental principles of mass transfer for the simulation of the oil and moisture content change during the Deep-Fat Frying of plantain (ipekere) chip. The explicit Finite Difference Technique (FDT) was used to conduct a numerical solution to the consequential governing equation (partial differential equation) that was used to describe the mass transfer rate during the process. Computer codes that were computed in MATLAB were used for the implementation of FDT at diverse frying conditions. Samples of the plantain were cut into portions of 2 mm thickness, and these sliced portions were fried at separate frying oil temperatures (170, 180 and 190°C) between 0.5 and 4 minutes. The experimental data and the predicted outcomes were compared for the validation of the model, and the juxtaposition revealed a plausible agreement. The predicted values and the experimental values of oil and moisture transfer models produced correlation coefficients that range from 0.96 to 0.99 and 0.94 to 0.99, respectively. The predicted outcomes could be utilized for the control and design of the DFF.

Mots clés

  • mass transfer
  • moisture loss
  • oil uptake
  • frying
  • plantain
access type Accès libre

Mathematical Modelling of the Mechanical Properties of Four Varieties of Brine Pickles Using Neural Networks

Publié en ligne: 24 Dec 2020
Pages: 257 - 268

Résumé

Abstract

The study assesses the impact of selected fruit properties and the souring process parameters on the mechanical properties of four varieties of field cucumbers (Śremianin, Śremski, Polan and Izyd) harvested from 2014 to 2016. The analyses focused on the changes in the values of the puncture strength parameters of the peel and the mesocarp, the deformation from the moment of puncture and the energy needed to puncture the peel and the mesocarp of the selected cucumber varieties relative to the year of harvest, fruit size, type of brine, puncture location and souring time. Neural networks were used to model the relationships studied. Sensitivity analysis of the obtained models showed that the length fraction had the greatest impact on the puncture strength and the energy needed to puncture the peel and the mesocarp. On the other hand, deformation was most affected by the souring time and the brine composition.

Mots clés

  • cucumber
  • puncture strength
  • neural modelling
  • sensitivity analysis
access type Accès libre

Characteristics of Technological Properties of Grain and Flour from Ancient Varieties of Wheat (Einkorn, Emmer and Spelt)

Publié en ligne: 24 Dec 2020
Pages: 269 - 278

Résumé

Abstract

The study presents assessment of commodity characteristics of grains from ancient varieties of wheat (einkorn, emmer and spelt) in comparison to grains of the conventional wheat cultivar Arkadia. The findings related to the grain of einkorn and emmer were very similar, and far worse than those related to spelt grain; the latter were found with better ratings, sometimes even in comparison to the conventional wheat grain (e.g. the highest mass-weight density). Similar relationships were observed between the flours produced by milling the grains. Analysis of the indirect baking quality indicators showed that flours from einkorn and emmer can effectively be used for baking purposes, however they present low technological value. The flour from emmer wheat was found to be the poorest, which was confirmed e.g. by the low gluten number, gluten index, Zeleny’s index, and high gluten spreadability. Spelt flour was found to present moderate technological value. Based on the results it can be concluded that by using adequate modification in the process of dough kneading and fermentation it will be possible to produce high quality baked goods from ancient wheat grains.

Mots clés

  • einkorn wheat
  • emmer wheat
  • spelt
  • assessment of grain as a commodity
  • baking properties of flour
access type Accès libre

Effect of Tytanit® on the Physiological Activity of Wild Strawberry (Fragaria vesca L.) Grown in Salinity Conditions

Publié en ligne: 24 Dec 2020
Pages: 279 - 288

Résumé

Abstract

Progressive global warming and decreasing freshwater resources are forcing to look for alternative solutions in plants cultivation. The use of saltwater and cultivation in saline areas becomes increasingly common. Wild strawberry is a rich source of antioxidant compounds beneficial for human health. The aim of the study was to investigate the effect of Tytanit® on the physiological activity of wild strawberry grown under different salinity levels (32.5, 50 and 100 mM L−1 NaCl). Assimilatory pigments content, free proline concentration, chlorophyll fluorescence and relative water content were measured at two phenological phases BBCH 15 and 60. Results analysis revealed that the applicability of Tytanit® to mitigate physiological stress in wild strawberry caused by salinity did not produce the desired effect.

Mots clés

  • chlorophyll-a
  • chlorophyll-b
  • carotenoids
  • proline
  • chlorophyll fluorescence
  • water balance

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