Food Technology
Elnaz Milani; Zahra Dehghan; Neda Hashemi
Abstract
Abstract:1 Introduction: Gastrointestinal diseases are very important among human societies, especially in developing countries. One of these diseases, celiac disease, is the result of the interference of gluten in food, the body's immune system, genetics and environmental factors. Therefore, it is necessary ...
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Abstract:1 Introduction: Gastrointestinal diseases are very important among human societies, especially in developing countries. One of these diseases, celiac disease, is the result of the interference of gluten in food, the body's immune system, genetics and environmental factors. Therefore, it is necessary to provide a solution for the production of gluten-free products and also to improve their quality. The increase in the nutritional knowledge of the people of the society has caused the development and production of healthy food products for certain groups to have a growing trend. Baked products such as cookies are very popular among the society because of their textural characteristics as well as flavoring and attractive colors. Therefore, their enrichment is of interest. Most commercial gluten-free bakery products are based on pure starch or the combination of corn starch with gluten-free flour, which is associated with dryness and sandiness in the product. Materials and methods: The aim of this research wass to investigate the functional characteristics of non-extruded and extruded chickpea flour samples and then the effect of adding different levels of it at three levels of 0, 20 and 40% on physicochemical characteristics, textural characteristics, Lightness, porosity and sensory using completely randomized factorial design. The blend of chick pea flour- xanthan gum was extruded by a parallel twin-screw extruder (Jinan Saxin, China). Process was applied at die diameter of 3 mm, and extrusion temperature of 140 ℃. The chemical composition of raw materials was measured by standard AOAC (2000) methods. The hardness of cookies was measured using Texture Analyzer (TA plus Ametek, UK). The cylinder steel probe (2 mm diameter) was set to move at a speed of 1 mm/s The samples were punctured by the probe to a distance of 10 mm. The color parameters L* (lightness), a*(redness), b*(yellowness) values of the samples were determined by the Hunterlab machine (Reston VA, US) (Rhee et al, 2004). Water absorption index in terms of grams of bonded water was calculated by the sample. Sensory evaluation was performed using a 5-point hedonic test. Results and discussion: In general, gluten-free products are unable to store carbon dioxide gas due to the lack of a coherent and uniform gluten network, which causes an increase in volume. As a result, the product is small in volume and the structure of the crumb is compressed. The extrusion baking process had a high potential to improve cookie quality; In such a way that the addition of extruded chickpea flour increased the porosity of the cookie samples, the results of the texture analysis show that the addition of extruded chickpeas up to a minimum of 40% improved the texture of the cookie and also increased its shelf life. Also, the sensory test results showed the favorable effect of adding extruded chickpea flour up to 20%. concequently, by summarizing the results of physical and sensory tests, it was determined that cookies with appropriate sensory and quality characteristics can be produced using 40% of extruded chickpea flour. Peas, and especially extruded peas, due to their protein and dietary fiber content, high water absorption ability, while maintaining moisture, reduced the hardness of the cookie texture. Considering the increase in demand for gluten-free products, it seems that enriching these products with nutrients such as chickpea flour can be an alternative method to improve the nutritional value of these products. Adding legumes is a good way to increase the consumption of legumes, which are rich in the amino acid lysine. Legumes, especially pea seeds, have high nutritional value and functional characteristics, and including them in the diet by adding them to bakery products is a good way to increase their consumption. The use of chickpea flour as a nutrient source in cookie formulation increases the nutritional value, reduces the glycemic index and improves the variety of such products.
Food Technology
Elham Ghiami; Arash Koocheki; Elnaz Milani
Abstract
Introduction Quinoa, which is known as the mother grain,has higher protein content than common cereals and possesses a large lysine content. Quinoa is composed mainly of carbohydrates (60-75%), of which 10-13% is dietary fiber. Quinoa also has a slightly higher protein content (12-16%) compared ...
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Introduction Quinoa, which is known as the mother grain,has higher protein content than common cereals and possesses a large lysine content. Quinoa is composed mainly of carbohydrates (60-75%), of which 10-13% is dietary fiber. Quinoa also has a slightly higher protein content (12-16%) compared with cereal grains and fat content (5-9%) that is rich in unsaturated fatty acids. Quinoa seeds contain similar or slightly higheramounts of bioactive compounds such as polyphenols (2.7-3.8 g/kg). Moreover, quinoa is gluten-free, thus providing the ability to enhance the selection of gluten-free products forconsumers with celiac disease, but this type of characteristicis challenging to development of bakery products from quinoa with desirable physicochemical properties. Processing of cereal grains and pseudo-cereals into products that deliver a nutritive valueto consumers represents a considerable opportunity for large scale food processing. There havebeen some reported studies on roasting, extrusion, steam pre-conditioning and pearling of quinoafor further uses. Extrusion cooking is a promising technology for improvement of functional properties of quinoa flour. The Evaluation of physicochemical properties and microstructure of Expanded quinoa as affected by extrusion conditions was the main goal of this project. Material and Methods In this study, a parallel twin-screw extruder (Jinan Saxin, China) with die diameter of 3 mm was applied. The effects of extrusion process parameters including feed moisture content (14 and 16%) and die temperature (130, 150 and 170 °C) on final moisture content, bulk density, water absorption index (WAI), color parametersL* (lightness), a*(redness), b*(yellowness), hardness, and microstructure of Expanded quinoa were studied. Extrusion was carried out using a co-rotating twin screw extruder with L/D ratio of 10:1 and die diameter of 4 mm. The feed rate of flour and the screw speed were set at 40 kg/h and 200 rpm, respectively. The physicochemical properties were measured using standard methods. The hardness measurement was performed by a texture analyzer. The cylinder steel probe (2 mm diameter) was set to move at a speed of 1 mm/s The samples were punctured by the probe to a distance of 10 mm . The color parameters of the samples were determined by the Hunterlab machine. The morphology of samples was assessed using a scanning electron microscopy (SEM). Results and Discussion A comprehensive study on impacts of extrusion processing conditions on quinoa flour was conducted. The effect of process variables on the physicochemical attributes of the extrudates was observed. the expanded quinoa with higher feed moisture content had greater moisture and those extruded at higher die temperatures showed lower moisture content (p<0.05). Moisture can reduce the shear force as a plasticizer and increase the amount of moisture absorption of the product. While increasing the die temperature, the effect of shear force on starch dextrification increases and reduces moisture absorption (p<0.05). WAI was significantly influenced by extrusion variables. In fact, feed moisture content and die temperature both positively changed the WAI of quinoa flour so that all extruded samples had significantly higher WAI than the untreated sample (p<0.05). Moreover, the sample with the higher feed moisture content (24%) treated at the highest extrusion temperature (170 °C) showed the largest and lowest water absorption and Hardness respectively (p<0.05). Another important feature of expanded quinoa is the lightness index, the results revealed that extrusion cooking caused a reduction in L* and enhancements in a* and b*. While changes in color parameters were more pronounced at more severe die temperature, higher feed moisture content counteracted the effects of cooking temperature on the color of the products. As expected from changes in the abovementioned color parameters, the sample with lower feed moisture content (16%) treated at the highest extrusion temperature (170 °C) experienced the greatest color change (ΔE). The texture profile analysis (TPA) indicated that higher feed moisture content yielded extrudates with harder texture whereas, extrusion at higher temperature resulted in lower hardness. The scanning electron micrographs showed that the native quinoa flour encompassed both small- and large-sized starch granules while the extruded sample mainly consisted of disaggregated particles. Furthermore, extrusion cooking of samples with higher feed moisture content caused formation of more uniform starch aggregates with smoother surfaces.
