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Volume 13, Issue 2, 2024
Online ISSN: 2182-1054
Volume 13 , Issue 2, (2024)
Published: 18.10.2024.
Open Access
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Contents
18.01.2020.
Original scientific paper
A numerical model for studying the thermal denaturation-aggregation of whey proteins under continuous thermal processing
A computational fluid dynamics model was designed to study the problem of thermal processing of a liquid food product containing whey proteins within a heat exchanger consisting of heating, holding and cooling tubular sections. This physical problem is associated with strong coupling between the phenomena of fluid flow, heat transfer, and thermal denaturation-aggregation of whey proteins. Our primary objective was to investigate the two-way coupling between these phenomena within the heat exchanger. This was carried out by analyzing the model predictions of velocity, temperature and product properties at both axial and radial directions. Attention was focussed on the whey proteins present in a cream cheese formulation. The thermal denaturation-aggregation kinetics was supposed to follow that of the beta-lacto-globulin, which plays a major role in fouling when milk derivatives are submitted to thermal processing in heat exchangers. Model predictions demonstrated that the apparent viscosity of the liquid product exhibited a complex behavior along the processing unit: in addition to its dependence on local temperature, it was affected by the local degree of denaturation of whey proteins – and hence on the product history previous to this position in the heat exchanger. The numerical model was structured into a sequence of computational domains; its versatility was illustrated by changing the length of the holding section and then assessing the impact on the final degree of denaturation of the whey proteins present in the liquid product.
Artemio Plana-Fattori, Christophe Doursat, Alienor Coutouly, Alain Riaublanc, Denis Flick
18.01.2020.
Original scientific paper
Evaluation of the effectiveness of cereal bran extract for sunflower oil stability during frying
This study evaluated the effectiveness of black rice, millet and barley bran extracts against oxidative degradation of sunflower oil in frying, by determining the total antioxidant activity, total phenolic content, free fatty acid content, conjugated diene content and total polar content. It was reported that the total phenolic content rice bran was approximately three times higher than that of the millet bran extracts and five times higher than the results for barley bran extracts. The total antioxidant activity results for barley bran and rice bran extract (40.95 ± 0.07and 40.87 ± 0.04 Trolox equivalent μmol/g of bran, respectively) were two times higher than that of millet bran extract (17.16 ± 0.34 Trolox equivalent μmol/g of bran). The results of the effectiveness of the cereal bran extracts were significantly different (p<0.05). The free fatty acid content of the rice bran and propyl gallate enriched oil samples showed better results (2.02 ± 0.01% and 1.62 ± 0.00%) than millet, barley and control enriched oil samples (3.43 ±0.01%, 3.13±0.01% and 6.13 ± 0.01% respectively). In the same vein, conjugated diene content results from all the enriched oil samples indicated that the rice bran enriched oil sample had the least amount of secondary oxidized products compared to the other enriched oil samples. It can be concluded that rice bran extract can be used for frying without discarding or replenishing the oil.
Abayomi W. Ajala, Abdollah Ghavami
18.01.2020.
Original scientific paper
Textural, rheological and sensory properties of spreadable processed goat cheese
The aim of this work was to study the influence of the ripening degree of natural goat cheese on texture, rheological and sensory properties of processed cheese products. Processed cheeses were formulated using goat cheeses with 10, 20, and 40 days of ripening. We obtained four different formulations by varying the proportions of these cheeses in each formulation. The variation in major α, β, and para-κ casein fractions, rheological properties, and the texture of samples were determined, and a sensorial evaluation was carried out. Cheeses from Formulation 2 (50% cheese ripened for 10 days, 25% cheese ripened for 20 days and 25% cheese ripened for 40 days) had greater values of α and β –caseins, which is related to a greater content of intact casein resulting from a cheese with short ripening time. Hardness, adhesiveness and complex modulus (G*) decreased as the degree of ripening of the natural cheese (raw material) increased. Formulation 2 presented a G* value similar to that of the commercial processed cow cheese and the greatest firmness. Formulation 2 presented the characteristics we aimed to obtain, described as spreadable, slightly acid and salty cheese.
Laura Burgos, Nora Pece, Silvina Maldonado
24.02.2021.
Original scientific paper
Chickpea Protein Isolation, Characterization and Application in Muffin Enrichment
The aim of this study was to enhance the nutritional value and the functional characteristics of muffins by enriching with chickpea protein isolate, while keeping their rheological characteristics. Chickpea Protein isolate (CPI) was prepared by alkaline solubilization (pH 11), followed by isoelectric precipitation at pH 4.5. SDS-PAGE revealed three subunits with molecular weights of 47, 30 and 85 kDa; representing the globulin fractions, legumin-like and vicilin-like proteins. Maximum protein solubility (83.32%) was obtained at pH 11. CPI exhibited an emulsifying activity index of 25.17 m2 g-1, emulsion stability index of 14.09 min. The foaming capacity and stability were 62% and 94.49%, respectively. Water and oil absorption were 3.65 and 2.30 mL g-1, respectively. CPI was added to muffin batter at 0, 2.5, 5, 7.5 and 10%. CPI fortifieded muffins showed reduction in moisture content, which influenced texture profile analysis through increasing hardness, gumminess and chewiness values. Additionally, both protein content and protein digestibility of muffins increased to 22.2 and 94.08%, respectively. CPI-enriched muffins were darker (lower L) with yellowish crumbs (higher b). Finally, preliminary sensory evaluation showed high consumer acceptance for CPI-enriched muffins.
Sobhy Ahmed El Sohaimy, Marageta A. Brennan, Amira Galal Darwish, Charles S. Brennan
18.01.2020.
Original scientific paper
Improvement of microbiological quality of hen egg powder using gamma irradiation
Eggs and their products such as desserts, confectioneries, bakery mixes, mayonnaise and many convenience foods have been implicated in food-borne disease outbreaks due to microorganism contamination. The effect of gamma irradiation on the presence of microorganisms in egg powder was investigated. Egg powder samples were exposed to several doses of irradiation: 0, 5, 10 and 15 kGy and stored for up to 12 months at ambient temperature (25 oC). Results indicated that the total viable count (TVC) (5.56 log10 cfu g-1), total coliform counts (TCC) (6.46 log10 cfu g-1) and mold and yeast counts (MYC) (9.12 log10 cfu g) in un-irradiated (control) samples of egg powder were higher than the maximum limits (4.88, 2.00 and 1.70 log10 cfu g-1, respectively). Application of the higher doses (10 and 15 kGy) decreased the TVC, TCC and MYC of the egg powder samples to less than 1 log10 cfu g-1 and the counts remained almost constant during storage for 12 months. D10 values for Escherichia coli and Salmonella typhimurium were 0.714 and 0.278 kGy, respectively. Gamma irradiation treatment could be chosen on the basis of preliminary microbiological tests including TVC, TCC and MYC and help improve the hygienic quality by killing and reducing the microorganisms that might be present inside of egg powder to meet national and international standards.
M. Al-Bachir
24.02.2021.
Original scientific paper
Effect of Taro (Colocasia esculenta) Enrichment on Physicochemical and Textural Properties of Cake
Taro is a plant widely produced in tropical areas for its underground corms and it is used mainly as a vegetable. Its physicochemical, sensory properties and health benefits led to its use in value-added products. The cake is a high value-added bakery product and it needs a lower amount of gluten protein, therefore, taro flour (TF) was supplemented in wheat flour (WF) at different levels (10, 20, 30 and 40%). In connection with this, the incorporation of taro flour into wheat-based products has been reported to increase their nutritional and textural quality. The taro-supplemented cake showed higher mineral and fiber content, however, reduced caloric value. It was observed that taro supplementation reduced gluten and protein content and had higher oil and water binding capacity, therefore suitable for cake preparation. Taro cake had improved texture and sensory characteristics in comparison to wheat cake. It can be concluded that addition of taro for cake preparation improves nutrition and quality characteristics, therefore, it can be recommended to use taro for cake preparation.
Anuj Saklani, Ravinder Kaushik, Prince Chawla, Naveen Kumar, Mukul Kumar
18.01.2020.
Original scientific paper
Effect of modified atmosphere packaging on quality of Barhi dates at Khalal stage
Barhi Dates are an important food and often consumed and sold in the market during the stage Khalal, when the colour is yellow and their taste is sweet with the disappearance of their astringent taste. During the Khalal stage, these dates become physiologically mature with gives the sweet taste. For this reason, they are sold and consumed in a short period of time before these fruits turn into Rutab, a stage at which they lose that distinguishing characteristic. The high moisture, rapid ripening, and delays in transportation or improper storage conditions quickly result in Rutab stage. Thus The Khalal stage lasts for a short time until the fruits get ripe. In the present study, Barhi Khalals were packaged in air (control) and by two types of modified atmosphere packaging: MAP A (5% O2+ 20% CO2 and 75% N2) and MAP B (40% O2+ 20% CO2 and 40% N2). Afterwards, all samples were stored at 5°C for 30 days. On days zero, 10, 20 and 30 of storage, the fruits were evaluated in terms of the changes in the quality indices of weight loss, colour, Total Soluble Solids (TSS), and firmness of the fruits and sensory features. The results showed that the minimum weight loss was 0.45% in modified atmosphere packaging, especially with MAP A and the minimum increase in the TSS was 37.35 Brix° after 30 days of the storage. On the other hand, the results for firmness, colour, and sensory evaluation were better with control packaging.
hayder jumaah
18.01.2020.
Original scientific paper
The effect of in vitro enzyme digestion on antioxidant and anticholinesterase potential of tomato (Lycopersicum esculentum) fruit and two commercially processed tomato pastes
Tomato is a horticultural crop of interest, that is widely consumed fresh or as processed products. The present investigation was to evaluate the antioxidant indices (total phenolic content, flavonoid content, ferric reducing antioxidant power, radical scavenging activities, inhibitory action against lipid oxidation) and anti-cholinesterase action (acetylcholinesterase and butyrylcholinesterase) of tomato fruits (ripe and unripe) and pastes (paste 2 and paste 1) after simulated gastrointestinal digestion. The total phenolic content (mg/g GAE) of the In vitro digested tomato fruits and pastes showed higher values (ripe tomato: 61.08; tomato paste1: 56.02; tomato paste 2: 60.36; unripe tomato: 38.97) than the ethanolic extracts, with digested ripe tomato ranking higher. Similar results were also obtained for total flavonoid content, ferric reducing antioxidant power, and the radical scavenging activities (DPPH*, ABTS˙+, NO*, OH*), with the in vitro digested samples ranking high. The ability of the enzyme digested and ethanolic extracts of tomato fruits and pastes to inhibit iron and sodium nitroprusside induced lipid oxidation in rat’s liver and brain homogenate increased in a concentration dependent manner, with the enzyme digested tomato fruits and pastes ranking high. Similarly, the ability of the in vitro digested tomato fruit and pastes to enhance activities of the antioxidant enzymes (GPx, GSH, SOD and Catalase) and to inhibit the formation of cholinesterases ranked high. The result of this investigation showed that the studied tomato fruit and pastes possess antioxidant and anti-cholinesterase activities that would be bio-available after the gastrointestinal digestion and by implication could be harnessed as functional food.
SULE SALAWU, Olatunde F. Faloye, Bukola B. Ola-Salawu, Akintunde A. Akindahunsi
18.01.2020.
Original scientific paper
Optimization of pressure parboiling conditions and pre-conditioned moisture content of brown rice (unpolished rice) for microwave puffing and its comparison with hot sand bed puffing
Brown rice puffing (unpolished rice) gives a more nutritious product compared to traditional puffed polished rice and reduces the cost of the product significantly, even though, the rice bran layer resists expansion during puffing. In the present study, brown rice was puffed in a microwave and hot-sand-bed after its pressure parboiling. Pressure parboiling parameters, steam pressure (196, 294, 392, 490 kPa) and steaming time (5, 10, 15 min), along with pre-conditioned moisture content (8, 10, 12 % wb) were studied and optimized for puffing characteristics (puffing percentage, expansion ratio, whiteness index, bulk density and hardness). All the experiments were carried out using a full factorial design. Statistical analysis showed there was a significant effect of processing variables on puffing characteristics. Optimized steam pressure, steaming time and pre-conditioned moisture content for microwave puffing were found to be 303.6 kPa, 14.25 min and 11.6% (wb) respectively, and for hot-sand-bed puffing to be 260.7 kPa, 15 min and 8% (wb) respectively.
Ajay Swarnakar, Prem Prakash Srivastav, Susanta Kumar Das
24.02.2021.
Original scientific paper
Chemical Characteristics and Sensory Properties of Novel Snacks Produced with Okara Fortified with Omega-3 from Fish Oil
The aim of the present work was to develop a new soy-based food product and evaluate its chemical and sensory properties. A soy-based snack was mixed with rice (Oryza sativa), fortified with eicos-apentaenoic acid (EPA) and docosahexaenoic acid (DHA) Omega-3 fatty acids from sh by-products in encapsulated and emulsion form. Soy beans were subjected to grinding processes, maceration in pure distilled water, filtration and pasteurization, to obtain vegetable drinks and generate solid residue. Finally, a sensory analysis of the product obtained was carried out. The snacks protein content was around 17%. From the sensory evaluation, it could be concluded that the snacks with 50% of okara had great acceptability and the addition of Omega-3 was also acceptable. So, okara represents an excellent raw material that can be utilized for dietary protein fortification. On the other hand, it proposes based on soy and fish by-products allow sustainable development and contribute to the economy of each sector.
Trinidad Sandra Álvarez, Daniela Lorena Lamas