Ayhan Topuz

Influence of different drying methods on carotenoids and capsaicinoids of paprika (Cv., Jalapeno).

Influence of Refractance Window™ Drying (RWD), a novel contact drying method, on carotenoids, capsaicinoids, Retinol Activity Equivalent (RAE) and Scoville Heat Unit (SHU) of paprika (Cv., Jalapeno) was investigated in comparison with freeze drying (FD), oven drying (OD), and natural convective drying (NCD) methods. Eight carotenoids (capsanthin, capsorubin, capsolutein, β-carotene, β-cryptoxanthin, mutatoxanthin, violaxanthin and zeaxanthin) and five capsaicinoid analogues (capsaicin, dihydrocapsaicin, homodihydrocapsaicin, isodihydrocapsaicin, nordihydrocapsaicin) were identified in paprika. All these components were significantly (P<0.05) decreased by the RWD, FD and OD methods. However, due to ongoing synthesis, the NCD method resulted in higher carotenoids, except violaxanthin and mutatoxanthin, and capsaicinoids content than those of the others, even puree. Mutatoxanthin, naturally occurring pigment in red pepper, could only be detected in FD paprika. The highest RAE and SHU values, which were derived from the data of carotenoids and capsaicinoids, respectively, were also determined in NCD paprika.

Mixture Design Approach in Wall Material Selection and Evaluation of Ultrasonic Emulsification in Flaxseed Oil Microencapsulation

Flaxseed oil, sensitive to oxidation, was systematically microencapsulated with six triple wall materials combinations [carbohydrate (maltodextrine and two different modified starches (N-Lok® and HiCap® 100)); protein (sodium caseinate, whey protein concentrate); and Arabic gum] for the highest microencapsulation efficiency and oxidation stability. Proportions of the triple wall materials were optimized in mixture design using the quadratic model. Effects of Ultra-Turrax and ultrasonic emulsifications on microencapsulation efficiencies were additionally characterized in the optimized wall material combinations. The microcapsules produced were investigated for particle size distribution, moisture content, water activity, bulk density, and oxidative stability. Results showed that the combination of modified starch (Hi-Cap® 100)/Arabic gum/whey protein concentrate (4/0/1, w/w/w) provided the highest efficiency in flaxseed oil microencapsulation. However, the only successful combination in preventing flaxseed oil oxidation was maltodextrine/Arabic gum/whey protein concentrate (4/0/1, w/w/w). The microcapsules produced by ultrasonic emulsification had higher microencapsulation efficiency than that of Ultra-Turrax emulsification.

Effects of Baking and Boiling on the Nutritional and Antioxidant Properties of Sweet Potato [Ipomoea batatas (L.) Lam.] Cultivars

The effects of baking and boiling on the nutritional and antioxidant properties of three sweet potato cultivars (Beniazuma, Koganesengan, Kotobuki) cultivated in Turkey were investigated. The samples were analyzed for proximate composition, total phenolic content, ascorbic acid, β-carotene, antiradical activity, and free sugars. The dry matter, protein, and starch contents of the sweet potatoes were significantly changed by the treatments while the ash and crude fiber contents did not differ as significantly. The β-carotene contents of baked and boiled sweet potatoes were lower than those of fresh sweet potatoes; however, the total phenolic and ascorbic acid contents of the baked and boiled sweet potatoes were higher than those of the fresh samples. Generally, the antiradical activity of the sweet potatoes increased with the treatments. Sucrose, glucose, and fructose were quantified as free sugars in all fresh sweet potatoes; however, maltose was determined in the treated samples. In terms of the analyzed parameters, there were no explicit differences among the sweet potato cultivars.

Effect of vegetable proteins on physical characteristics of spray-dried tomato powders

In the present study, the effectiveness of different vegetable proteins (pea protein isolate, soy protein isolate and zein from maize) at two different ratios (1% and 5%) on product yield and physical properties of spray-dried pulpy tomato juice was investigated. Additionally, these proteins were compared with whey protein concentrate which has a superior effect on spray dried products at the same concentrations. Additionally, plain tomato juice was also spray dried for comparison with vegetable proteins. The product yield of the tomato powders dried with the vegetable proteins was lower than with the whey protein concentrate. Among vegetable proteins, the highest product yield was produced with 1% soy protein isolate. In all products, there was a slight colour difference between the reconstituted tomato powders and the raw tomato juice, which indicated that pulpy tomato juice can be spray dried with minor colour change. All powders had unique free-flowing properties estimated as Carr index and Hausner ratio due to their large particles.

Functional properties of chickpea protein isolates dried by refractance window drying

In the present study, the effect of Refractance Window (RW) drying on the functional properties of chickpea protein isolates was investigated and compared to freeze drying at different pH levels. The functional properties investigated were protein solubility, water and oil holding capacity, emulsifying properties, foaming properties, flocculation and coalescence indices and textural properties. The solubility, oil holding capacity and foam stability of the freeze dried protein isolates were determined to be higher than the RW dried samples. On the other hand, the RW dried samples had better water holding capacity and emulsion stability compared to the freeze dried protein isolates. The emulsion activity index, flocculation and coalescence indices of the chickpea protein isolates prepared by different drying techniques showed different tendencies depending on the pH level. Freeze dried protein isolates exhibited higher gelation ability than RW dried samples according to the texture profile analysis. This study clearly showed that the drying technique used in the preparation of protein isolates can affect their functional properties.

Nanoencapsulation of Fish Oil and Essential Fatty Acids

Fish oils and essential fatty acids have many beneficial effects on human health. However, these oils and fatty acids are sensitive to environmental factors. Thus, nanoencapsulation is used by different methods such as nanoemulsification, nanoliposomes, solid lipid nanoparticles (SLNs), nanostructured lipid carriers, and biopolymer nanocarriers to increase the stability and controlled release of these oils. Additionally, nanoencapsulation increases their bioavailability. Therefore, this chapter will give an overview for these nanoencapsulation methods, their application in fish oils and essential fatty acids, release characteristics, and characterization of fish oil-loaded nanocapsules.

Microencapsulation of Plant Oils Rich in Alpha-Linolenic Acid: Effect of Processing Parameters

Alpha-linolenic acid (ALA) is an omega-3 fatty acid naturally occurring in plant oils. Omega-3 fatty acids have many beneficial effects. However, these fatty acids are sensitive to environmental factors such as heat, oxygen, metal ions, and humidity. Thus, these oils are microencapsulated by different methods. There are several methods for oil encapsulation, including spray drying, spray chilling, freeze-drying, fluid bed coating, coacervation, and extrusion. Among these techniques, spray drying is one of the most preferred and widely utilized in microencapsulation of plant oils rich in ALA. Different processing parameters affect the quality and stability of the microencapsulated oils. This chapter reviews the effects of processing parameters such as wall materials and their concentrations, oil loading, feeding temperature, air inlet and outlet temperatures, emulsification, atomization, and aspiration rate on the microencapsulation by spray drying of plant oils rich in ALA.Alpha-linolenic acid (ALA) is an omega-3 fatty acid naturally occurring in plant oils. Omega-3 fatty acids have many beneficial effects. However, these fatty acids are sensitive to environmental factors such as heat, oxygen, metal ions, and humidity. Thus, these oils are microencapsulated by different methods. There are several methods for oil encapsulation, including spray drying, spray chilling, freeze-drying, fluid bed coating, coacervation, and extrusion. Among these techniques, spray drying is one of the most preferred and widely utilized in microencapsulation of plant oils rich in ALA. Different processing parameters affect the quality and stability of the microencapsulated oils. This chapter reviews the effects of processing parameters such as wall materials and their concentrations, oil loading, feeding temperature, air inlet and outlet temperatures, emulsification, atomization, and aspiration rate on the microencapsulation by spray drying of plant oils rich in ALA.

THE USE OF ULTRASOUND IN FRUIT JUICE PROCESSING

Emerging nonthermal technologies have raised great interest, because conscious consumers are demanding healthy, nutritious and equivalent to fresh products. In this regard, ultrasound has been identified as one of the promising nonthermal alternative methods in fruit juice processing. The use of ultrasound on its own in the food industry for microbial and enzyme inactivation is currently insufficient. However, ultrasound applications can also be used in combination with chemicals, pressure and temperature to increase efficiency. With ultrasound application, producing of higher quality, tasty and nutritious juice is possible because enzymes and microorganism can be inactivated at lower temperatures than thermal treatments. In this study, it has been compiled the advantages, disadvantages and usability of ultrasonic processes in the fruit juice industry. It is assessed necessary to raise awareness of the use of this process in the juice industry, the sector and scientists to be involved in comprehensive research by ensuring collaboration.

Strawberry drying: Development of a closed-cycle modified atmosphere drying system for food products and the performance evaluation of a case study

ABSTRACT In the present study, a closed-cycle modified atmosphere drying (CC-MAD) system was developed as an alternative drying technique to facilitate drying processes for agricultural commodities appropriate to highly humid and sunny regions with a better quality. An absorption dehumidifying system was designed for working pseudo-continuously with the most efficient absorbent in terms of moisture absorption, desorption rate, and capacity. The system, assisted by a solar panel for absorbent regeneration, was tested, while its optimum working condition was determined by strawberry drying. This unique process was comparatively carried out using hot-air and freeze-drying techniques in terms of processing time and final product quality. Strawberry slices (5 mm thickness) were dried successfully using CC-MAD. The optimum drying conditions of CC-MAD were determined as drying temperature of 60°C, drying air/gas velocity of 3 m/s and drying medium oxygen level of 9.47%. The loss of ascorbic acid was significantly reduced by CC-MAD technique. These losses were found to be 2.9, 6.9, 27.2, and 23.8% by freeze-drying, CC-MAD, hot-air drying, and hot-air drying combined with CC-MAD, respectively. The total monomeric anthocyanins loss was also significantly reduced by the CC-MAD technique (20.3%), in a similar way to that of freeze-drying (18.1%) in comparison with hot-air drying (40.4%). In addition, CC-MAD (12,446 kJ/kg fresh product at 4 h drying time) is three times more advantageous in terms of energy cost compared with freeze-drying (30492.8 kJ/kg fresh product at 24 h drying time) and six times faster in terms of drying time. This new drying system can be used as an alternative to freeze-drying in the drying of foods, especially in products sensitive to oxidation.