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Volume 13, Issue 2, 2024

Online ISSN: 2182-1054

Volume 13 , Issue 2, (2024)

Published: 18.10.2024.

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18.04.2020.

Original scientific paper

Bacterial diversity, biogenic amines and lipids oxidation in traditional dried anchovy (Encrasicholina punctifer) during ambient storage

This study aimed to elucidate the effect of ambient storage (23±2°C, 68% RH) on the bacterial load and diversity, biogenic amines and lipids oxidation in traditional dried anchovy (E. punctifer) in order to evaluate its safety, quality and stability during 12 weeks of storage. Total aerobic bacteria (TAB), Staphylococcus aureus, Enterobacteriaceae (ENT), histidine decarboxylating bacteria (HDB), lysine decarboxylating bacteria (LDB) and ornithine decarboxylating bacteria (ODB) were enumerated and identified by conventional, VITEK 2 compact and sequencing of 16S rRNA gene methods. Histamine, cadaverine and putrescine contents were determined by high performance liquid chromatography. Lipid oxidation was evaluated by peroxide value (PV). Total aerobic bacteria, S. aureus, ENT, HDB, LDB and ODB initial counts of log10 4.9 ± 0.85, 3.7 ± 0.57, 4.2 ± 0.05, 3.7 ± 0.72, 3.9 ± 0.40 and 4.1 ± 0.24 CFU/g respectively did not significantly change (p > 0.05) during 12 weeks of storage. A high bacterial diversity of 27 species belonging to 20 genera was found, with the dominance of S. aureus, Acinetobacter lwoffii and S. warneri and the first incidence of Psychrobacter celer, Desemzia incerta, Granulicatella elegans and Bhargavaea indica in dried fish.  Initial histamine, cadaverine and putrescine contents and PV of 5.2 ± 4.3, 8.5 ± 1.9 and 5.8 ± 0.6 mg/100g and 0.19 ± 0.02 meq/kg respectively did not significantly change (p > 0.05) during 12 weeks of storage. This study found that ambient storage at 23±2°C, 68% RH for 12 weeks did not affect the bacterial load,  biogenic amines and lipids, and that the dried anchovy remained microbiologically safe and of good quality.

Ismail Al Bulushi, Nejib Guizani, Mutamed Ayyash, Mohammed Al Za'abi, Aisha Abushelaibi, Hilton C. Deeth, Zahra Al Kharousi, Fathiya Al Hamadani, Salha Al Maskari, Jamila Alkalbani

18.04.2020.

Original scientific paper

Mango peel ingredient as salt and phosphate replacement in chicken breast marinade

Whole mango peel powder and fibre extracted from mango peel were investigated as potential ingredients to replace salt and phosphate in chicken marinade. Whole mango peel powder possessed higher water absorption capacity than mango peel fibre, 4.57% and 1.47%, respectively (P < 0.05). Similar oil absorption capacity was observed in both mango peel ingredients (P > 0.05). Purified pectin and sorbitol syrup were also used to compare the water holding capacity in marinated chicken breasts. Mango peel ingredients exhibited less cooking loss than pectin and sorbitol syrup, however, higher cooking loss than sodium tripolyphosphate (STPP) and NaCl (P > 0.05). Marinating with mango peel ingredients significantly increased a* value of chicken breasts after cooking, while L* and b* values were similar in marinating with NaCl (P > 0.05). Hardness of frozen fully cooked chicken breast was measured after thawing. The lowest shear force of 7.13 N was observed in chicken breasts marinated with mango peel fibre (P < 0.05), while the hardness of chicken breasts marinated with whole mango peel powder was not significant different from STPP and NaCl treatments. Results from this study revealed a potential approach of utilizing fruit waste as an ingredient to substitute phosphate and salt in chicken marinade.

Sunisa Roidoung, Napatsawan Ponta, Ruttapong Intisan

18.04.2020.

Original scientific paper

Zizyphus lotus (L.) extracts as prebiotics in the aggregation and adhesion of probiotic and inhibition of pathologic bacteria from patients with colorectal cancer

The mucosal surfaces of the intestinal tract harbor a complex microbiota. Bacteria enter in contact with intestinal cells and bestow important nutritional, metabolic and protective functions which benefit the host. Various factors are able to alter the balances between different intestinal bacteria. Dysbiosis has been described in various pathologies and metabolic diseases in humans, such as cancer. Colorectal cancer pathology can benefit from gut microbial imbalance. Its overgrowth may lead to acute symptoms. An alternative strategy to restore this balance is the use of plant extracts which exhibit a prebiotic activity by stimulating of probiotic bacteria and antimicrobial activity against pathogenic bacteria colonization. The present study aims to evaluate the in vitro antioxidant and antibacterial activity of phenolic extracts (Aqueous extract "AE" and Methanolic extract "ME" ) from Zizyphus lotus. It aims also to investigate the effect of this extract as a prebiotic on the aggregation of probiotic and inhibitory effects of pathogenic bacteria isolated from faeces of patients with colorectal cancer. Phytochemical analysis of different extracts from Zizyphus lotus by HPLC showed that all are rich in phenolic compounds (225.40 mgAGE/gDW for AE and 63.04 mgAGE/gDW for ME extracts). Moreover, all extracts showed an important antioxidant activity (227 µg/ml for AE and 195 µg/ml for ME). These extracts also exhibited a significant prebiotic effect and antibacterial activity. Characterization of the in vitro effect of the aqueous extract showed that the percentage of autoaggregation and adhesion of probiotic and inhibitory effects of pathogenic bacteria increased in the presence of aqueous extracts.

Sara Ouldchikh, Aicha TirTouil, Boumédiene Meddah

18.04.2020.

Original scientific paper

Chemical constituents in leaves and aroma products of Nicotiana rustica L. tobacco

Nicotiana rustica L. (Aztec tobacco) is the only Nicotiana species, except common tobacco (N. tabacum L.), which is cultivated for tabacco products. The leaves of N. rustica, however, accumulate various specialized metabolites of potential interest. Therefore, the objective of this study was to evaluate certain classes of metabolites (by HPLC and GC-MS) in the leaves, the essential oil (EO), concrete and resinoid of N. rustica. Three pentacyclic triterpenes were identified in the leaves (by HPLC): betulin (252.78 µg g-1), betulinic (182.53 µg g-1) and oleanolic  (69.44 µg g-1) acids. The dominant free phenolic acids in the leaves (by HPLC) were rosmarinic (4257.38 µg g-1) and chlorogenic (1714.40 µg g-1), and conjugated forms of vanillic (3445.71 µg g-1), sinapic (1963.11 µg g-1), and syringic (1784.96 µg g-1). The major flavonoids in the leaves were luteolin (960.44 µg g-1), apigenin (880.66 µg g-1) and hyperosid (780.72 µg g-1). The GS-MS profiling of the EO identified 19 components and the major ones were phytol (43.68 %), solanone (5.54 %), cis-5-butyl-4-methyldihydrofuran-2(3H)-one (5.23 %), dihydro-β-ionone (4.25 %), α-ionene (3.54 %),and β-damascenone (3.03 %). The major volatiles in the concrete were  isoamyl alcohol (28.82 %), oxynicotine (9.02 %), phytol (7.80 %), 4-mеthyl-1-penthanol (6.33 %), cotinine (5.55 %) and 3-metyl-3-penthanol (4.09 %). Resinoid composition was dominant by nicotine (39.75 %), phytol (11.23 %), eicosane (4.88 %), diethyl phthalate (4.19 %), dibutyl phthalate (3.48 %) and solanone (3.27 %). Concrete and resinoid showed weak antibacterial activity . These results create grounds for considering N. rustica as a source to obtain aroma or other bioproducts.

Venelina Popova, Tanya A. Ivanova, Albena S. Stoyanova, Violeta V. Nikolova, Margarita H. Docheva, Tzveta H. Hristeva, Stanka T. Damyanova, Nikolay P. Nikolov

18.10.2020.

Original scientific paper

Assessment and Evaluation of Student Learning Through a Project-Based Assignment on Note by Note Cooking

Many innovative teaching and learning methods are used in higher level education including project-based learning (PBL). Since 2012 a PBL assignment project has been undertaken by master students of the Advanced Molecular Gastronomy module at Technological University Dublin (TU Dublin). The aim is to stimulate student learning and creativity by using Note by Note cooking in a PBL assignment while at the same time complying with the requirements of the annual International Note by Note contest which is held in Paris, France. Direct and indirect assessment methods were used to assign individual grades and to gather student feedback about the module. The direct methods were both formative and summative. The indirect method used was a student feedback questionnaire. Results to date (2012-2019) showed that 92% of learners successfully passed the module. However, further evaluation of individual assessment results revealed that most students achieved higher scores for finding and using resources, asking further questions and developing their own answers than for analysing, synthesising and evaluating information (P≤0.01). Overall students were happy with the module content and said that they learnt about Note by Note cooking, chemical compounds, researching, independent-thinking and perseverance. In future students should carry out a more in-depth analysis, synthesis and evaluation of information.

Róisín M. Burke, Pauline Danaher

18.04.2020.

Original scientific paper

Effect of olive pulp enrichment on physicochemical and antioxidant properties of wheat bread

Black and green olive pulp was added to wheat bread formulation at different levels (5, 10, 15%) with the aim to improve its nutritional value by enhancing the phenolic content and antioxidant capacity. Additionally, the effects of the fortification with olive pulp on the physical characteristics, staling rate and overall consumer acceptability of the formulated breads were explored. Both olive pulps exhibited significantly higher antioxidant activity than refined wheat flour. Baking imparted an impressive increase in TPC, TFC and antioxidant activity of breads as revealed by comparison of experimental with theoretical values but returned significant differences only in the case of TPC when a two-tailed t-test for paired data was applied. Texture measurements showed a substantial increase in hardness with storage along with decreasing loaf volume and increased density. Hydroxytyrosol was the major phenolic compound of fortified breads followed by tyrosol. Olive pulp could be incorporated in a bread formulation without interfering with the general sensory acceptability.

Anna Marinopoulou, Maria Papageorgiou, Maria Irakli, Dimitrios Gerasopoulos

18.04.2020.

Original scientific paper

Evaluation of growth and cereulide production by Bacillus cereus isolated from cooked rice

Conditions influencing Bacillus cereus growth and cereulide production, such as temperature and pH, were evaluated at varying incubation periods. The growth and cereulide production at different temperatures and pH values ranging from 10 to 40 ºC and 5.0 to 8.5, respectively showed that the temperature from 20 to 30 ºC and at pH from 6.0 to 7.0 gave the optimum growth and cereulide production by B. cereus SA105. pH below 6.0 resulted in reduced growth and cereulide production. Cereulide production increased along with the incubation period, and maximum cereulide titre (ng/mL) of 1219.1±8.90 was obtained after 6 days of incubation at 30 ºC and pH 6.5 under static conditions. There was no quantifiable toxin at incubation temperatures of 10 and 40 ºC by B. cereus SA105. This work further reveals that B. cereus growth and cereulide production was significantly affected by temperature and pH in relation to the incubation period. Furthermore, the findings of this study will serve as a means for reducing the diversity of emetic toxin-producing B. cereus population in food and food products, thus preventing food poisoning.

Damilola Seyi-Amole, Abiodun A. Onilude, Dasari S. Rani, Prakash M. Halami

01.12.2018.

Professional paper

Development and incorporation of nanoemulsions in food

Currently, nanoencapsulation of bioactive compounds is promising, and is one of the methods that has been proven very effective. The development of food-grade nanoemulsions is in a state of constant innovation due to the interesting features that this method of encapsulation has, such as small droplet size, kinetic stability and appearance. With this technology, it is possible to control some food properties, such as texture, taste and stability. In this article, we present a review of the most commonly used methods in the creation of nanoemulsions, the recent developments of these dispersions, the relevant applications of nanoemulsions in food matrices, the most commonly used food-grade materials and the functionality of nanoemulsions, which are designed primarily to encapsulate compounds with biological activity. Nanoemulsions have been shown to be effective in preventing degradation and improving the bioavailability of bioactive compounds, such as oil-soluble vitamins, antimicrobials, flavours and antioxidants. At the end of this article, facts of interest about acceptance issues and nanotechnology regulatory policies in the food industry are presented.

Antonio de Jesus Cenobio-Galindo, Rafael G. Campos-Montiel, Rubén Jiménez-Alvarado, Isaac Almaraz-Buendía, Gabriela Medina-Pérez, Fabián Fernández-Luqueño

01.12.2018.

Professional paper

Effects of “starch:water” ratio on gelatinization of pinhão starch from nine germplasm collections, measured by Differential Scanning Calorimetry

Native starch was extracted from nine germplasm collections of Araucaria angustifolia seeds in aqueous medium and they were characterized by Pasting Properties (RVA), X-ray Powder Diffractometry (XRD) and Scanning Electron Microscopy (SEM). The gelatinization process of each sample was evaluated at different ratios of starch:water by Differential Scanning Calorimetry (DSC). A slight displacement in the gelatinization curves was observed for the pinhão starches prepared with different amounts of water. With an increase in water content, most of the samples presented a decrease in the peak, the conclusion temperatures, and the range of gelatinization temperatures, while the enthalpy did not follow a standard behavior. A displacement or a narrowing of the gelatinization temperature range occurred with increasing water content.  Pinhão starch showed pasting temperature in the range of 60-67 °C and there were differences in the pasting properties and degree of relative crystallinity between the analyzed samples. The C-type diffraction pattern was found for all the samples and the morphology of starch granules was similar, with oval and round shapes. Therefore, different characteristics were found among starches from nine germplasm collections, encouraging the protection of the biological diversity of selected species, aiming at future applications.

Camila D. Bet, Rossane C. B. Godoy, Layse P. Cordoba, Ivo M. Demiate, Luiz G. Lacerda, Egon Schnitzler

01.12.2018.

Professional paper

Effect of osmotic drying on physicochemical properties of pansies (viola × wittrockiana)

The objective of this work was to study the effect of osmotic drying, using different hypertonic solutions (sucrose and sodium chloride), on physicochemical characteristics of pansies (Viola × wittrockiana). The same treatments were applied to lettuce to compare the behavior of flowers with other vegetables. Pansies' superhydrophobic surface structure, called papillae, increased the resistance to exchanges with hypertonic solutions. No weight loss was observed after most treatments (sucrose: between 2.2 and 6.8 %; NaCl: between -23.0 % and 1.5 %), aw maintained high values (>0.94) and monomeric anthocyanins were preserved (fresh 0.10 and 0.19 mg Cy-3glu/g fresh matter for 20%/1 h in NaCl and 60%/1 h in sucrose). When applying more drastic conditions, as sodium chloride for more than 1 hour, undesirable textural and color changes were observed. For lettuce, all treatments caused osmotic dehydration, weight loss (ranged between -9.3 to -30.3 % for 80%/1 h in sucrose and 15%/1 h in NaCl) and a reduction on aw (<0.97) and carotenoids, with sodium chloride causing more damage in visual appearance than sucrose. Therefore, immersion in osmotic solutions can be applied to lettuce but the desired effect was not achieved for pansies due to the morphological structure of the flowers' epidermis.

Luana Fernandes, Susana Casal, Agostinho Magalhães, Paula Baptista, José A. Pereira, Jorge A. Saraiva, Elsa Ramalhosa

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