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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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18.10.2018.

Original scientific paper

Production of camel milk yoghurt: physicochemical and microbiological quality and consumer acceptability

The objectives of this study were to make yoghurt from camel milk and determine its physicochemical, microbiological and sensory qualities. The quality of camel milk yoghurt was compared with cow milk yoghurt and all parameters were analyzed following standard procedures. Yoghurt of acceptable consistency was made from camel milk using 1.2% gelatin, 5% bovine skim milk powder, 1.5 ml/L of calcium chloride, 40 ml/L of maple strawberry syrup and 6% yoghurt culture (YF-L811) and by incubating the milk at 42°C for 18 h. The average values for moisture, ash, syneresis, pH, titratable acidity and total solids of camel milk yoghurt were 83.4%, 1.13%, 58%, 4.37, 1.255% lactic acid and 16.7%, respectively. The corresponding values for cow milk yoghurt were 80.6%, 0.71%, 56%, 4.67, 0.865% lactic acid and 19.5%, respectively. The titratable acidity of camel milk yoghurt was significantly higher (P<0.05) than cow milk yoghurt; however, no significant difference was observed between the two yoghurt types for the other parameters. Coliforms were not detected in both yoghurt types. The sensory analysis showed that cow milk yoghurt was more preferred by the panellists than camel milk yoghurt. Production of yoghurt from camel milk using the same procedure as for cow milk yoghurt proved to be difficult.  Further research is called for to improve the acceptability of camel milk yoghurt using locally available and acceptable flavouring agents. Research needs to be conducted to optimize the operating parameters and standardize the production procedures of camel milk yoghurt in the future.

Obakeng Galeboe, Eyassu Seifu, Bonno Sekwati-Monang

18.10.2018.

Original scientific paper

Antioxidant and antibacterial activities of exopolysaccharides produced by lactic acid bacteria isolated from yogurt

The objectives of this study were to optimize the conditions for cell growth and exopolysaccharides (EPS) production by using pure and mixed microbial cultures of Streptococcus thermophilus and Lactobacillus bulgaricus, and to evaluate the antioxidant and antibacterial activities of EPS in vitro. The mixed cultures of two strains showed a higher cell growth whereas the higher EPS production was detected in pure culture with S. thermophilus. The optimal medium were determined as follows (g/l): sucrose 50, yeast extract 10, KH2PO4 3 , MgSO4.7H2O 0.05 and pH initial 6.5 at 30°C. Under the optimized conditions, the values of dry cell weight (DCW) and EPS were 5.2± 0.8 g/l and 56.8 ± 0.62 mg/ml, respectively.  The EPS demonstrated a positive antioxidant potential on DDPH radical scavenging. The agar diffusion assay showed that purified EPS exhibited antibacterial activities against tested pathogens such as Escherichia coli ATCC 250922 and Staphyloccocus aureus ATCC 250923 at (62-1000) μg/mL. In conclusion, EPS have an antioxidant activity and could have applications in the food industry.

Benattouche Zouaoui, Djillali Bouhadi, Ghalem Bachir Raho

18.10.2018.

Original scientific paper

‘Made-in-transit’ yoghurt processing: a review of basic concepts and technological implications

The manufacture of food during distribution, a concept known as “made-in-transit” (MIT) manufacture, has the potential to expand the distribution range, extend shelf-life, and provide the customer with the freshest possible product. Benefits for the manufacturer include maximising throughput while minimising manufacturing space and inventory. This concept is new, with mushrooms being the only MIT food developed so far. The feasibility of developing an MIT product from a fermented food was reviewed using yoghurt as a model system. Through the alteration of some of the yoghurt manufacturing parameters (e.g. milk base formulation, heat treatment, starter culture composition and fermentation temperature) it is possible to develop this form of yoghurt production. A predictive microbiology approach is suitable for predicting the effects of both time and temperature on designing and predicting the fermentation process. This review demonstrates the potential of the MIT concept for a fermented food.

Nor Khaizura Mahmud Ab Rashid, S. H. Flint, O. J. McCarthy, J. S. Palmer, M. Golding, A. Jaworska

18.10.2018.

Original scientific paper

A nutritional evaluation of the berry of a new grape: 'Karaerik' (Vitis vinifera L.)

Grape berries are a good source of nutrients and nutraceuticals and have many benefits for human health. Growing interest in the export potential and consumption of a new grape (cv. Karaerik), cultivated as a table grape in Turkey, encouraged us to profile its major nutrient contents from six different locations. Due to its popularity, the nutritional value of this grape berry needs to be investigated to ascertain its potential economic and health benefits. The most abundant sugars in the grape berry were fructose and glucose (peel/whole fruit; averages 236.57 and 127.87, and 183.36 and 108.60 (g kg-1 fresh weight), respectively), while the major organic acids were tartaric and malic acids (7.17 and 2.81, and 2.61 and 1.76(g kg-1 fresh weight), respectively). Linoleic acid (peel/whole fruit/seed; 37.14, 33.12 and 57.83%, respectively) was the predominant fatty acid, while potassium (peel/whole fruit/seed; 9331.5, 10226.33 and 5354 mg/g dry weight, respectively) was the predominant mineral, followed by phosphorus (1592.8, 2672 and 3072.67) in the berry. Our results demonstrate that the nutrient components and physicochemical parameters varied significantly among the sampling locations. The grape berry contains considerable quantities of potentially beneficial healthy nutrients worthy of further evaluation.

Aynur Kurt, Nesrin Colak, Aydin Sükrü Bengu, Ali Gundoğdu, Erdal Akpınar, Sema Hayirlioglu-Ayaz, Faik Ayaz

18.10.2018.

Original scientific paper

Physicochemical and antioxidant properties of banana varieties and sensorial evaluation of jelly prepared from those varieties available in Sylhet region

The present research aimed to evaluate and compare the antioxidant activity in both pulp and peel and the physicochemical contents in the pulp of four local varieties of banana, i.e. Musa acuminata species named Sagor, Champa, Shail and Bichi, available in Sylhet region of Bangladesh. The antioxidant activity from a methanolic extract of banana peels and pulps was evaluated by determination of total phenolic content and DPPH scavenging activity. The physicochemical contents of banana pulp such as protein, fat, moisture, ash and carbohydrate were also determined. The results showed that the overall antioxidant activity of banana peel was higher than the pulp of banana. The pulp of the Shail variety had the highest antioxidant activity (TPC = 80.14 mg GAE/100 g, DPPH radical scavenging activity =91.37%) among the four varieties. Fat (1.38%) and moisture (76.23%) contents were higher in the pulp of Shail, while protein (1.82%) and carbohydrate (22.71%) contents were higher in the pulp of Bichi. The Champa variety contained higher ash content (1.05%). Among the jellies prepared from those banana varieties, the jelly of the Shail variety showed the highest score for overall acceptance (6.8) whilst the jelly prepared from the Bichi variety showed the highest score for taste (7.75). This may be due to higher carbohydrate content. The study suggests that banana peel could be used in the food industry as a raw material to produce bakery products and in cosmetics and pharmaceutical industries as an antioxidant supplement.

Abdullah A. Sad, M. M. Hoque, Wahidu Zzaman

18.10.2018.

Original scientific paper

Consumers’ willingness to consume cassava leaves as a leafy vegetable in the Kumasi Metropolis, Ghana

This study employs the logit model to assess the determinants of consumers’ willingness to consume cassava leaves as a leafy vegetable in the Kumasi Metropolis of Ghana. A multistage sampling technique was used to select 180 respondents for the study. The study found that majority (76%) of the respondents had no knowledge of the nutritional value of cassava leaves, though they had consumed the product before. The empirical results showed that socioeconomic characteristics of respondents such as age, sex, household size and monthly income, as well as their perceptions on the attributes and use of cassava leaves as food have significant influence on willingness to consume cassava leaves as a leafy vegetable. There is the need to provide information on the nutritional benefits of cassava leaves to facilitate decision-making on its utilisation/consumption. Programmes aimed at promoting the consumption of cassava leaves should consider the significant variables that have influence on the consumption of the product.

Fred Nimoh, Godfred O. Asare, Ismael Twumasi, Richmond Anaman

18.10.2018.

Original scientific paper

Are we doing our homework? An analysis of food engineering education in Brazil

What is the profile of Food Engineering education in Brazil? Are we following the contemporary professional renewal trend? Driven by these questions, the present study analyzed data regarding 21 academic courses, which represent approximately 22% of the total bachelor’s degree in food engineering courses offered in the country. Samples were defined considering a Brazilian annual ranking of undergraduate programs: very good (four stars) and excellent (five stars). Next, information was recovered from both the Brazilian Ministry of Education and institutional homepages of each analyzed program. The results suggest that food engineering programs exhibit relative identity, naturally due to their history and the path of each program and their faculty, shaping particularities in how fields of knowledge are constituted, in addition to their representativeness in the total workload of the program. However, initial analysis is suggestive regarding understanding that Brazil is not properly doing its homework, based on global movement, concerning food engineering education. The need to rethink Brazilian technical education, without culminating in additional workload, is emphasized, not only regarding new materials and technologies for learning and teaching, but also in terms of bringing a human and market approach. The achievement of this complex goal seems to be provided by the encouragement of student associations, transversal learning processes, and learning experiences outside the classroom as a means of improving undergraduate programs and human resources.

Vivian-Lara Lara Silva, Fausto Makishi, Marcus Magossi, Izabel Cristina Freitas Moraes, Carmen Silvia Favaro Trindade, Paulo Jose do Amaral Sobral

18.04.2017.

Original scientific paper

In vitro investigation of antioxidant activities of Launea taraxacifolia and Crassocephalum rubens

Launea taraxacifolia and Crassocephalum rubens are among many wild, underutilized and under cultivated vegetables in Nigeria that are at risk of extinction. Total flavonoid contents (TFC), total phenolic contents (TPC), and antioxidant activities of different concentrations (1-5 mg ml−1 ) were evaluated; using in vitro assays to assess the scavenging properties of 2, 2-diphenyl-1-picryl hydrazyl (DPPHRSP), nitric oxide (NORSP) and hydroxyl (OHRSP). Phenolic profiles of the alcoholic extracts were characterized using high-performance liquid chromatography techniques. The results revealed higher TFC (mg/100g RE) in aqueous (6.06±0.02-78.79±0.01) than alcohol extracts (with methanol 0.93±0.01—12.73±0.04, and with ethanol -0.85±0.01–7.70±0.03). In a similar trend, OHRSP (%) was higher in aqueous extracts (40.83±0.10–91.74±0.19) than alcoholic extracts (with methanol - 11.67±0.3–30.83±0.06; and with ethanol -14.42±0.06-40.27±0.05). TPC (mg/100g GAE) which was higher in alcoholic extracts (with methanol -21.48±0.01–133.20±0.16 and with ethanol -9.45±0.01– 59.73±0.02) than aqueous extracts (14.83±0.01–52.64±0.03) was in agreement with the trend observed for NORSP (28.24±0.05-151.76±0.08 for methanolic extracts, 21.99±0.13–49.93±0.04 for ethanolic extracts and 38.47±0.11–86.15±0.05 for aqueous extracts). DPPHRSP was also higher in alcoholic extracts (methanolic -22.81±0.01-48.41±0.05 and ethanolic–14.53±0.01-62.68±0.07) than aqueous extracts (13.66±0.13–42.86±0.03). TFC, TPC and antioxidant activities showed concentration dependent increase and strong positive correlation with TFC (r= 0.926 – 0.997and r= 0.432 – 1.000) and TPC (r= 0.825 – 0.999 and r= 0.473 - 0.994) for L. taraxacifolia and C. rubens respectively. Caffeic acid, chlorogenic acid, ellagic acid, quercetin and kaempferol were identified as major phenolic components in the extracts. The vegetables have high antioxidant potential for promoting good health; which could be attributed to the identified phytochemicals in them.

Funmilayo B. Borokini, Lajide Labunmi

18.04.2017.

Original scientific paper

A methodological approach for optimum preservation results: The packaging paradigm

The food preservation hypothesis as impacted by overall packaging applications is considered in this work. The objective was to devise a decision supportive method for the selection of “just-right” packaging materials, techniques and procedures. For that, food preservation was critically approached in order to identify the optimum outcome at experimental and packaging selection decision-making levels. A mathematically supported and proven knowledge classification, and the establishment of a straightforward coherence mode among the principles of the natural systemic phenomena, were used. The ultimate aim of this work was to justifiably surpass a simple description of packaging according to its measurable specifications, and instead, engage its inherent properties into a cyclic 8-steps-process for eventually understanding its potential to support any particular preservation hypothesis in question. The proposed methodology includes primarily, the consideration of the study hypothesis and, in parallel, the conclusive remarks and claims with respect to the experimental factors involved (properties, parameters, relations and conditions). Considering the experimentally controlled set-ups that a researcher has to expose the food system to and the role of packaging in obtaining its preservation potential, our method supports the experimenters in selecting the experimental conditions under which the preservation hypothesis can be disclaimed and furthermore, it could indicate the way to reduce experimentation research waste.

ANTONIOS KANAVOURAS, Frank A. Coutelieris

01.12.2016.

Professional paper

Impact of selected polyphenolics on the structural properties of model lipid membranes – a review

This review is a presentation of data gathered on the interactions of several polyphenolics (i.e., phenolic acids, stilbenes, flavonoids) with lipid bilayers of different lipid compositions. These polyphenolics have been investigated through a combination of fluorescence spectroscopy, electron paramagnetic resonance spectroscopy, and differential scanning calorimetry, to detect changes in membrane fluidity. Among the investigated phenolic acids, the least polar phenolic acid, p-coumaric acid, has the greatest effect on lipid membrane structure. It appears to have a greater ability to cross membranes by passive transport than more polar phenolic acids. On the other hand, among the flavonoids that have been studied, the anthocyanins cyanidin 3-glucoside and its aglycone are inactive. All of the flavonols tested, except for epigallocatechin-3-gallate, promote small decreases in membrane fluidity. Computer simulation of electron paramagnetic resonance spectra for flavonoids indicated two or three regions in the phosphatidylcholine/ phosphatidylserine (2.4:1) membrane with different fluidity characteristics. The effects of the different flavonoids are correlated to their structural characteristics, whereby even the difference in one -OH group can be important, as can the number of H-bonds they form. The role of membrane composition and flavonoid structure in these interactions with lipid membranes are of great importance for bioavailability of these compounds and for their biological effects in an organism

Nataša P. Ulrih, Ajda Ota, Veronika Abram

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