Food Technology
Mahtab Moradnia; Akram Arianfar; Ali Mohamadi Sani; Zahra Sheikholeslami
Abstract
IntroductionDonut is a type of sweet fried snack which is usually produced from leavened and deep fried dough. The deliciousness and high energy of donut has made it very popular among sweet products made from wheat flour. The sensitivity of wheat flour to weather conditions as well as bad economic conditions ...
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IntroductionDonut is a type of sweet fried snack which is usually produced from leavened and deep fried dough. The deliciousness and high energy of donut has made it very popular among sweet products made from wheat flour. The sensitivity of wheat flour to weather conditions as well as bad economic conditions in recent years led to perfomingt research to replacewheat flour with other grains. Quinoa is a rich source of protein (the essential amino acids lysine, methionine, cysteine, and threonine), magnesium, fiber, vitamin B, potassium, and other minerals such as iron. Quinoa seeds have less starch than other grains (wheat, barley, corn, and rice). The value of dietary fiber in quinoa is much more in comparison to other grains, it had about 31% insoluble fiber. Also, as a source of phytoestrogens, it prevents cancer, cardiovascular diseases, and osteoporosis. The main problem with quinoa to be used for human diet is the presence of saponin in the outer shell of the seed. Saponins are considered anti-nutritional agents due to their hemolytic activity on red blood cells, bitterness, foaming ability, and inhibition of enzymes. Therefore, the most important step for using quinoa in food products is to remove saponin. The other problem with using saponin its too bitterness hence causing bloating and heartburn. This study aimed to choose the best saponinization method from quinoa and the possibility of using the saponinization quinoa instead of wheat in donut formulation and investigation the quality, texture, and sensory properties of the donuts. Materials of Methods The methods for saponin removal include (maceration, microwave, ultrasound, wet method, and a combination of wet and dry methods) were compared. Donuts were produced with quinoa flour at two levels of 20 and 40% substitution. The Fiber, ash, and protein values of wheat flour, saponinized quinoa flour, and donuts with different levels of saponinized quinoa flour were measured. The effect of replacement wheat flour with saponinized quinoa flour on oil absorption, texture, SEM, and sensory properties of donuts was evaluated. Results and Discussion A comparison between different methods of saponinization indicated that the ultrasound method had the minimum efficiency in saponin removal and the highest amount of saponin removal was in the combined wet and dry methods, followed by the maceration method. The difference between the combined method and maceration was not significant and had the most influence in extracting saponin from quinoa flour. Of course, the maceration method is economically important due to the long time of the process and production of a lot of waste water leading to loss of nutrients from quinoa. The highest amount of protein, fiber, and ash was obtained in saponinized quinoa flour and a donut containing 40% quinoa flour. The amount of firmness, elasticity, SEM, and sensory properties in the sample with 20% quinoa flour had similar characteristics to the control sample, but increasing the amount of quinoa flour reduced these factors. The oil absorption percentage in donuts containing 40% quinoa flour was higher than in other samples. The results of using saponinized quinoa flour on the sensory characteristics (color crust and crumbs, taste, smell, texture and overall acceptance) of donuts showed that donut with 20% quinoa was similar to the control sample and was acceptable for panelists but increased the concentration up to 40% wasn’t pleasant. Conclusion In this study, the saponinized quinoa flour used in donut formulation to increase the nutritional value and reduced the calories of donuts also overcame the challenges of wheat shortage. The saponinization methods were compared to choose the method with the highest saponin removal. Then donut with saponinized quinoa flour was prepared. The use of saponinized quinoa flour as a replacement of wheat flour increased the nutritional value of donuts. Adding saponinized quinoa flour to the donuts formulation significantly declined the oil absorptions. Generally, the donuts containing saponinized quinoa flour had relatively similar sensory properties to the donuts with wheat flour (commercial donuts). Therefore, it seems that saponinized quinoa flour could be used successfully to improve the nutritional value of donuts and also consumers' acceptance.
Masoud Taghizadeh; Hesam Akhoondzadeh; Zahra Zamani
Abstract
Introduction: Grains are important food sources for human diet because of high protein content. There are different kinds of grains used as food worldwide. Today herbal proteins play an important role as food sources in societies. Herbal protein sources are actually strategic points for improving national ...
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Introduction: Grains are important food sources for human diet because of high protein content. There are different kinds of grains used as food worldwide. Today herbal proteins play an important role as food sources in societies. Herbal protein sources are actually strategic points for improving national dietary all over the world. (Mashayekh et al, 2008). Food experts are becoming more open to Quinoa, because of high protein content, (Dallagnol et al., 2013). FAO compares Quinoa grain with concentered milk powder considering high nutritional facts, and called grains as multi vitamin (FAO, quinoa, 2011). According to scientific reports quinoa grain can be replaced with rice in national dietary (Ferreira et al, 2015. Oelk et al., 1992). Quinoa originally cultivated in South America (barazil, Chile, Peru etc.) and known as semi-cereals (Schoenlechner&Berghofe2010).Furthermore, Quinoa flour is a highly nutritional alternative to feed animals as well as in the production of foods which are suitable for patients with celiac disease and gluten-sensitive patient worldwide. (Dallagnol et al, 2013). From the technological point of view, functional properties hold an important position, Water and oil absorption capacity, protein solubility, gelatinization capacity, foam ability and foam stability are the most important functional properties. (Kaur and Singh, 2007. Ameri shahrabi, 1390). Functional properties are affected by different parameters such as protein network structure, lipid, carbohydrate, temperature and pH, respectively. (Alukoand Yada, 1995). This study proposed to investigate the physicochemical properties of Quinoa flour of three different varieties and monitor the effect of pH on their functional characteristics Materials and methods: three different variety of Quinoa grain, originated and cultivated in Peru, were used for experiments, varieties were black (BLACK COLLANA), white (SALCEDO INIA) and red (PASANKALLA), respectively. Grains were grind by 75 degree in mesh and refrigerated during storage. Carbohydrate, fat, ash, moisture content and protein were measured by AACC, (2003) methods. Functional properties were also measured using scientific methods, Owusu-Apenten, (2002), Kaur and Singh (2007) and customized Adebowale et al, (2005) method which used to measure protein solubility, Water and oil absorption capacity, foam ability and foam stability, respectively. Emulsion capacity and emulsion stability were measured using majzoobi et al, (2012) method. Results and discussion: chemical properties are important in both technological and nutritional aspects, chemical characteristics were observed and reported for three studied varieties. Protein solubility known as the first criteria in protein functional properties (Asadpour et al., 2010), this parameter is influenced by pH and the least value were observed in pH=4.5 (protein isoelectric point). Water and oil absorption capacity is one of the most important characteristics in flours (Kinsella, 1979), this parameter is a physical phenomenon which is known as oil or water confined in non-polar protein chains that is dependent on protein spatial shape. (Kinsella, 1979؛ Kaur and Singh, 2007؛ Trayunham et al., 2007) responses led to 1.285, 1.475 and 1.295 for white, red and black varieties, respectively. Foam ability and foamstability, actually known as volume increase caused by fast stirring and usually results in convenient rheological properties in products texture like ice cream and bread.this parameter refers to the ability of protein to make stable foam aginst mechanical and Gravitational stresses and measured in a 90 min. period of time (Oladela & Aina,2007) (Kinsella,1979). Least responses in this case were observed in pH=4.5 which is an isoelectric range of pH for protein chains. Results were corresponded by responses of El Nasri and El Tinay (2007), Lawal) 2004(, Taghizadeh et al, (2017) and Asadpour et al (2010) about other semi-cereal grains. Last metered parameter was emulsifying ability and emulsion stability, emulsifying in protein structure is an equilibrium between hydrophilic and hydrophobic parts of protein and affected by alkaline range of pH (Ragab et al., 2003( this parameter is influenced by protein solubility which is in the least measures in isoelectric point (Feizi et al., 2013). Results had shown that foam stability would decrease during time passes. This may be due to the coupling of dispersed phase particles (oil droplets) over time. Concerning the effect of pH on emulsion stability, the results showed that the stability values at alkaline pH were higher than that of acidic pH, so that this stability at pH = 9 was significantly different from other pHs. Among the three varieties of quinoa, the amount of protein in the black variety (16.81%) was higher than the other varieties, which could be further investigated as a potential protein source. In addition, results indicate functional properties are influenced by pH, which means out of iso electric point, protein solubility increase and other fictional properties were improve followed.
