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.

Gum arabic is a dried, gummy exudate obtained from the stems and branches of Acacia senegal and Acacia seyal. In Kenya, gum arabic comes from Acacia senegal var kerensis although its exploitation for commercial and industrial application is marginal. Therefore, the aim of this study was to characterize and determine the effect of the gum from A. senegal var kerensis on the quality characteristics of set low-fat yoghurt compared to gum arabic from A. senegal var senegal, with a view to increasing its utilization locally. Yoghurt was prepared containing gum arabic at four concentrations (0.2%, 0.4%, 0.6%, 0.8% gum w/v).  Results showed that A. senegal var kerensis gum had higher molecular weight and gelling properties compared to A. senegal var senegal gum. In addition, A. senegal var kerensis gum was less susceptible to syneresis and showed a higher absolute viscosity compared to A. senegal var senegal gum at all concentration levels. Sensory evaluation revealed that addition of gum arabic significantly improved the body and the texture of the yoghurt. Therefore, A. senegal var kerensis gum is a better yoghurt stabilizer than gum arabic from A. senegal var senegal. An optimal gum concentration of 0.6% of A. senegal var kerensis gum in low-fat yoghurt is recommended from the results of this study.

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.

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.

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.

Different parameters in cider processing were evaluated using different cultivars of Norwegian-grown table apples measuring the quality of cider. Seven different apple cultivars were mixed into four different apple juice mixtures. In this experiment, we evaluated the maturation of the apples along with commercial cider yeast and spontaneous alcoholic fermentation. Other parameters were fermentation temperature and filtration along with content of polyphenols, organic acids and volatile compounds that was analysed as an effect of the fermentation process. Succinic acid was the major organic acid in apples and ciders. The different apple juice mixtures did not reveal pyruvic and acetic acids but they appeared in relatively high amount in the ciders. The level of citric acid increased from apple to cider. Chlorogenic acid was the major polyphenolic compound found from 13-109 mg L-1 in the apple juice mixtures and between 27-200 mg L-1 in the ciders. The higher alcohol 3-methyl-1-butanol appeared in relatively large amounts in all the ciders (91-166 mg L-1). The average content of acetaldehyde increased during the fermentation process, from apple juice mixtures 2.75 mg L-1 and 14.65 mg L-1 in the ciders. The content also increased for ethyl acetate with levels at 0.1 mg L-1 in the apple juice mixture and 20 mg L-1 in the cider. In the sensory evaluation experiment, the ciders produced from the apple cultivars Aroma, Gravenstein and Summerred got higher scores in fruitiness and complexity compared to the other apple juice mixtures.

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.

New functional foods and beverages can be developed using bioactive compounds present in pequi oil. Complex coacervation is an encapsulation method used for preserving bioactive molecules, especially those that are hydrophobic or sensitive to high temperatures. The objective of this work was to produce and characterize pequi oil microparticles using cashew gum/gelatin matrix (CG/GE) through complex coacervation. Gum Arabic (GA) was also studied in comparison with CG. The coacervation process was performed withoutpequi oil to determine the ideal proportions of the matrix components, followed by the embedding of the oil inthe microparticles for evaluation. Satisfactory microparticles were produced at pH 4.5 in the weight ratios of CG/GE = 2:1 and GA/GE = 1:3. Pequi oil release was greater in acidic pH, especially at pH 2 for the CG/GE matrix. The encapsulation efficiency for CG/GE and GA/GE was 72.53% (±4.80) and 82.77% (±6.09), respectively. The results showed that the CG/GE combination seemed very promising as anencapsulation matrix, especially for food applications involving pH values higher than 3.

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.

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.