ارزیابی ویژگیهای ضداکسیدانی و پری‌بیوتیکی آرد کینوا و بررسی پذیرش کلی استفاده از آن در یک دسرلبنی

Extended Abstract
Introduction: Pseudo-cereals are widely used for the development of functional foods. It has been shown that pseudo-cereals contain compounds such as fiber, proteins, lignin, amino acids, fatty acids, dietary fiber, minerals, phenolic compounds, vitamins, and more, which are beneficial for health. One of these beneficial pseudo-cereals is quinoa (Lazos et al., 1986). Quinoa, with the scientific name of Chenopodium quinoa Willd., is a good source of complete protein (including 9 essential amino acids), unsaturated fatty acids, minerals, vitamins, fiber, and antioxidants, making it known as a superfood (rich in minerals and vitamins) (Shilpi et al., 2016). Quinoa contains more phenols than all grains and pseudo-cereals, the most abundant being ferulic acid and quercetin (Tang et al., 2015). The antioxidant activity of quinoa is associated with its vitamin E content and phenolic compounds (Sadler et al., 2004). Quinoa also helps reduce various diseases, such as cardiovascular diseases, type 2 diabetes, certain cancers, high blood pressure, and obesity, and is a good choice for individuals with sensitivities to specific food groups (Shilpi et al., 2016). Quinoa has a high biological value (73%), similar to beef (74%) and higher than white rice (56%), wheat (49%), and corn (36%) (Kharis Sanchez et al., 2015). Including quinoa in the diet can be a good strategy for consuming high-biological value proteins and all essential amino acids (Gordillo Bastidas et al., 2016). According to the national standard of Iran No. 7110 of 2003, a dairy dessert is a product that typically uses milk and its derivatives, fruits and their derivatives, grains, nuts, and permitted additives in its production. The use of any preservatives in dairy desserts is prohibited. One of the essential features of these desserts is the high energy they receive and creating a pleasant feeling in the consumer due to the type of ingredients (De-Vic et al., 2003). Therefore, using quinoa flour, this nutritious pseudo-cereal, in combination with rice flour in producing dairy desserts such as porridge, can help produce a highly nutritious product for consumers.
Materials and Methods: White quinoa variety, rice flour, and sugar were purchased from the local Ahvaz market, and cow's milk and buffalo milk were bought from the animal husbandry station of Agricultural Sciences and Natural Resources University of Khuzestan, southwest of Iran. Then, quinoa flour was prepared using a BRAUN KSM2 mill. Twelve samples of dairy dessert containing various amounts (0, 50, and 100 percent) of cow and buffalo milk, quinoa flour (0, 20, 40, and 60 percent) were prepared with the formulation of milk (88.88%), flour (44.4%), and sugar (68.6%). For making the dessert, pasteurized milk was cooled, and after standardizing its fat content, sugar and a mixture of rice flour and quinoa flour were added to the milk and stirred to prevent clumping. It was stirred over the flame for 10 to 15 minutes until it reached the desired consistency. After cooling, the dessert was poured into disposable plastic containers and transferred to a refrigerator at 4°C for research tests on days 1 (24 hours after production), 7, and 14. The chemical compositions of the two flours were measured using standard methods. The moisture content of the flour was measured according to AACC 44-16, the ash content according to AACC 08-01, the fat content using the Soxhlet device and AACC 30-25, the protein content according to AACC 46-12, and the crude fiber content according to AOAC 43-991. The acidity and pH of the flour were also measured according to the national standard of Iran No. 11136. The antioxidant capacity of quinoa flour was determined using the DPPH method (Jayathilake et al., 2016). The prebiotic activity of this flour was examined in vitro on L. acidophilus. The pH of the environment was also measured by a pH meter to evaluate the metabolism of the flour (Hojjati et al., 2023). Some female Khuzestan Agricultural Sciences and Natural Resources University students evaluated the sensory acceptance of the produced dessert samples using a 9-point hedonic test and rated them on a scale of 1-10 (1 being the lowest and 10 being the highest). The results were analyzed using SPSS software version 18, and the means were compared with Duncan's test at a 95% confidence level. Charts were drawn using EXCEL software.

Discussion and Results: According to the results, the moisture content in rice flour and quinoa flour was determined to be (%7.75 ± 0.20) and (%8.50 ± 0.25) respectively. The ash content was (%0.60 ± 0.04) for rice flour and (%2.60 ± 0.10) for quinoa flour. The fat content in rice flour and quinoa flour was found to be (%9.90 ± 0.40) and (%15.88 ± 0.50) respectively. The protein content was (%8.93 ± 0.30) in rice flour and (%14.18 ± 0.50) in quinoa flour. The fiber content in rice flour and quinoa flour was (%2.20 ± 0.20) and (%3.60 ± 0.15) respectively. The pH levels were (6.61 ± 0.20) for rice flour and (6.31 ± 0.20) for quinoa flour, while the acidity levels were (%2.40 ± 0.30) for rice flour and (%6.00 ± 0.40 for quinoa flour. Furthermore, the total phenol content in quinoa flour was significantly higher than in rice flour (p < 0.05), with values of (139.96 ± 4.24) mg GAE/g in rice flour and (269.39 ± 2.41) mg GAE/g in quinoa flour. Shen et al. (2009) reported that the total phenol content is related to the color parameters of rice grain. In the study by Esfandiari et al. (2019), quinoa grain and leaf phenolic compounds and antioxidant properties were examined in laboratory conditions. The total phenol content in quinoa grain extract was 76.3 mg gallic acid per gram of extract, with major phenolic compounds being gallic acid, para-coumaric acid, caffeic acid, chlorogenic acid, quercetin, and kaempferol (Esfandiari et al., 2019). These differences could be due to differences in extraction methods, genotypes, soil types, and environmental conditions (Nsimba et al., 2008; Alvarez-Jubete et al., 2010). The DPPH free radical scavenging activity of quinoa flour is significantly higher than rice flour (p<0.05), with the amount in rice flour and quinoa flour being (81.62 ± 1.92) and (89.48 ± 0.29) micrograms per milliliter, respectively. Prebiotics are indigestible dietary fibers resistant to stomach acid, hydrolysis by mammalian enzymes, and absorption in the upper gastrointestinal tract and selectively stimulate the growth or activity of one or a few probiotic bacteria in the gut, benefiting the host's health. Results show that the number of bacteria in all substrates significantly increased compared to the initial number of probiotics (6 log cfu/ml) during the first 24 hours. On the first and second days, the highest bacterial survival rate was related to the 1% quinoa flour environment, and the lowest was the control environment. On the third day, the highest survival rate (8.85 ± 1.20 log cfu/ml) was related to the 0.5% and 1% quinoa flour environment, and the lowest number (6.20 ± 0.85 log cfu/ml) was related to the control environment. During this period, the growth of the probiotic L. acidophilus in the quinoa flour environment significantly differs from other environments, so quinoa flour can be considered a prebiotic compound. In the food industry, producing new products requires acceptance and approval from consumers. Therefore, evaluating and determining the best formulation by evaluators is necessary (Lukco & Delahanty, 2004; Behrens et al., 2007). According to the results, by increasing the replacement percentage of quinoa flour, the overall acceptance score of the samples significantly decreased. With the increase in storage time, the overall acceptance scores also significantly decreased. On the other hand, by increasing the replacement percentage of cow's milk with buffalo milk, the overall acceptance score increased, with the lowest overall acceptance score (7.67 ± 0.45) related to the dessert containing 60% quinoa flour and made with 100% cow's milk, and the highest overall acceptance score (9.01 ± 0.56) related to the dessert made with 100% buffalo milk and rice flour. The decrease in overall acceptance score with increasing the replacement percentage of rice flour with quinoa flour is the color, taste, and aroma of quinoa flour.
Conclusion: The results of the current study showed that quinoa flour is a pseudo-cereal with special nutritional value, high antioxidant capacity, and prebiotic potential and can be used to produce functional food products. Due to its distinctive aroma and flavor, quinoa flour can reduce consumers' overall acceptance of such products, which can be compensated by adding aromatic additives like vanilla and rose water in dairy desserts such as porridge.