Notes
Use of Quinoa Flour in The Production of Gluten-Free Tarhana
2014 Volume 20 Issue 5 Pages 1087-1092
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2014 Volume 20 Issue 5 Pages 1087-1092
Celiac disease is an immune-mediated enteropathy triggered by the ingestion of gluten in genetically susceptible individuals. Gluten is a complex mixture of storage proteins of wheat, rye and barley. However, pseudocereals do not contain gluten. Quinoa -one of three pseudocereals- has high level of protein, fat, fiber, vitamin, mineral and micro constituents, low level carbohydrate and it has good amino acid balance. The purpose of this study was to make gluten-free tarhana by using different ratios (40:30:30, 50:25:25 and 60:20:20%) quinoa flour (QF), rice flour and potato starch instead of wheat flour, and to determine the effects of QF addition levels on the some physical, chemical, nutritional, sensory properties of tarhana samples. The use of QF led to a decrease in fermentation loss values of the tarhana samples. Also, QF affected the colour (L*, a* and b*) of gluten-free tarhana. The tarhana samples containing 60% QF had the highest a* values, while tarhana samples containing 40% QF had the highest b* values. The use of high level QF (60%) increased crude protein, ash, crude fat, potassium, magnesium, calcium and iron contents in tarhana samples. Moreover, QF affected the scores of sensory properties of gluten-free tarhana soups. Tarhana soups prepared with 50% QF gave the highest scores for consistency and overall acceptability. In conclusion, gluten-free tarhana were satisfactorily improved in terms of chemical, nutritional and sensory properties nutritional properties by quinoa flour.
Cereal grains provide significant quantities of energy, protein and selected micronutrients in the animal and human diet (Dordevic, 2010). However, individuals with celiac disease can not consume cereal grains including gluten. Celiac disease occurs in genetically predisposed individuals who demonstrate a permanent intolerance to gluten, found in wheat, barley, and rye (Pietzak et al., 2001; Dewar et al., 2004). However, certain cereals (rice, maize, sorghum and millet) and pseudocereals (amaranth, buckwheat and quinoa) do not contain gluten. Especially, pseudocereals have been suggested to be safe for a gluten-free diet. Therefore, in the last decade, the use of pseudocereals was increased not only in allergic to cereals population, but also in common diets (Berti et al., 2005; Schulte Auf'm Erley et. al., 2005; Gorinstein et al., 2008).
Quinoa (Chenopodium quinoa), was important food in some ancient (Aztec, Mayan and Incan) civilizations of the past. Quinoa, one of the pseudo-cereal grains, native to the Andean regions of South America (Galway et al., 1990; Caperuto et al., 2001; Ng et al., 2007; Alvarez-Jubete et al., 2010a). In the last decade, the use of pseudocereals was increased not only in special diets for people allergic to cereals, but also in healthy diets (Gorinstein et al., 2008). Nowadays, quinoa is receiving considerable attention as an alternative crop in the World (Caperuto et al., 2001). Quinoa is promoted as an extremely healthy food of the future (gluten free). It is a food of the twenty-first century (Valencia-Chamorro, 2003).
Quinoa is considered a pseudocereal with proteins of high biological value, carbohydrates of low glycemic index, phytosteroids, and omega-3 and 6 fatty acids that bring benefits to the human health (Farinazzi-Machado et al., 2012). The nutrient composition is very good compared with common cereals. Its high components containing essential amino acids and unsaturated fatty acids (Ranhatro et al., 1993; Doğan and Karwe, 2003; Park and Morita, 2004; Stikic et al., 2012). The fatty acid composition of quinoa is chiefly linoleic acid, followed by oleic acid and palmitic acids (Ng et al., 2007). Moreover, they contain adequate levels of of important micronutrients such as minerals, vitamins (e.g. folic acid), and significant amounts of other bioactive components such as saponins, phytosterols, squalene, fagopyritols and polyphenols (Coulter and Lorenz, 1990; Repo-Carrasco et al., 2003; Alvarez-Jubete et al., 2010b; Schoenlechner et al., 2010; Valcárcel-Yamani and Lannes, 2012). Furthermore, it is a good source of dietary fiber (Alvarez-Jubete et al., 2010a).
The United Nations today highlighted the quinoa, known as an Andean “super food”, and other underused crops in the fight against hunger. The United Nations General Assembly has therefore declared 2013 as the “International Year of Quinoa”, in recognition of ancestral practices of the Andean people, who have managed to preserve quinoa in its natural state as food for present and future generations, through ancestral practices of living in harmony with nature (FAO, 2013).
This investigation was undertaken to produce a high nutritional characteristics food product using quinoa flour. Therefore, this study aimed to investigate the production of gluten-free tarhana with different ratios quinoa flour and to determine the physical, chemical, nutritional, sensory properties of tarhana samples.
Materials Quinoa groats were obtained from Bora Tarım Ürünleri, İstanbul, Turkey. Quinoa groats were ground in a hammer mill (Falling Number-3100 Laboratory Mill, Perten Instruments AB, Huddinge, Sweden) equipped with 0.5 mm opening screen. Whole QF (Quinoa Flour) was used in tarhana production. The ingredients used in tarhana production were purchased from local markets in Konya, Turkey. Quinoa flour, rice flour, potato starch, full fat strained yoghurt, tomato paste, compressed baker's yeast, chopped dry bulb onion, paprika, xanthan gum and salt were used in tarhana preparation. The spices used were in powder form (i.e., salt, paprika). The yoghurt was full-fat strained yoghurt (concentrated, “Süzme” yoghurt) made of cow's milk.
Preparation of tarhana samples The tarhana ingredients are presented in Table 1. Tarhana samples were prepared according to the method of Bilgicli et al. (2006). Gluten-free tarhana samples were made with QF, rice flour and potato starch at a ratio of “40:30:30” (40% QF), “50:25:25” (50% QF) and “60:20:20” (60% QF). Xanthan gum was added to gluten-free tarhana formulation as stabilizer. Tarhana ingredients were mixed using a Hobart mixer (Hobart N50, Canada Inc., North York, Ontario, Canada) for 5 min at the highest speed with distilled water (40 mL) added. The resultant mixtures were placed in sealed plastic container and incubated at 30°C for 72 h to ferment. During the fermentation, the mixture was mixed manually at every 12 h intervals. Fermented mixture was divided into 2 cm diameter pieces by hand, placed on aluminum trays and dried at 55°C for 48 h in an air convection oven (Nüve KD-200, Ankara, Turkey). The dried samples were ground into granulated form in a hammer mill (FN-3100 Laboratory Mill; Perten Instruments AB) equipped with 1 mm opening screen. Afterwards the tarhana samples were kept in closed glass containers at room temperature until used for analysis.
| Ingredients | Formula-1 (g) | Formula-2 (g) | Formula-3 (g) |
|---|---|---|---|
| (40% QF) | (50% QF) | (60% QF) | |
| Quinoa Flour (QF) | 40 | 50 | 60 |
| Rice flour | 30 | 25 | 20 |
| Potato starch | 30 | 25 | 20 |
| Yoghurt | 40 | 40 | 40 |
| Tomato paste | 10 | 10 | 10 |
| Qnion | 5 | 5 | 5 |
| Bakery's yeast | 2.5 | 2.5 | 2.5 |
| Xanthan gum | 2.5 | 2.5 | 2.5 |
| Paprika | 2.0 | 2.0 | 2.0 |
| Salt | 1.0 | 1.0 | 1.0 |
| Distilled water | 40 | 40 | 40 |
Chemical Analysis AACC International methods were used for the determination of ash (method 08 – 01), crude protein (method 46 – 12), crude fat (method 30 – 25), and crude fiber (method 32 – 10), contents of quinoa flour and tarhana samples (AACC, 1990).
Determination of fermentation loss Fermentation loss was found using the following formula; (Bilgiçli and Elgün, 2005).
 |
Determination of colour Colour measurement was performed using Hunter Lab Color Quest II Minolta CR 400 (Konica Minolta Sensing, Inc., Osaka, Japan). The color measurements were determined according to the CIELab color space system (Francis, 1998). Color was expressed as L* (100 = white ; 0 = black), a* (+, redness ; -, greenness), and b* (+, yellowness ; -, blueness).
Determination of mineral content The mineral (K, Mg, Ca, Fe and Zn) contents of the tarhana samples were determined by inductively coupled plasma atomic emission spectrometry (ICPAES) (Vista series, Varian International AG, Switzerland) with an automatic sampler system. Approximately 0.5 g of the tarhana sample was put into a burning cup, and 5 mL of HNO3 + 5 mL H2SO4 was added. The samples were incinerated in a microwave oven (Mars 5, CEM Corporation, USA). The solution was diluted to 100 mL with water. Concentrations were determined by ICP-AES (Bubert and Hagenah, 1987).
Sensory evaluation of tarhana Soups made from the tarhana samples were subjected to sensory evaluation. Tarhana soups were prepared by mixing 20 g tarhana sample with 200 mL distilled water (20°C) and simmering for 12 min over medium heat with constant stirring. Tarhana soups were evaluated by ten panelists, who are familiar with the characteristics of tarhana. Ages ranged from 23 to 42. Seven of them were females. Instructions were given in full to panelists beforehand. The samples (tarhana soups) were filled to porcelain bowl at 50°C and served to panelists under daylight room conditions. The panelists cleansed their palates with water before rating each sample. The panelists were asked to score the tarhana soups in terms of taste, colour, odor, consistency, sourness and overall acceptability using a 5-point scale with “1” being “dislike extremely”, “3” being “acceptable” and “5” being “like extremely”.
Statistical analysis A commercial software program (Tarist, version 4.0; Izmir, Turkey) was used to perform statistical analyses. Data were assessed by analysis of variance. Means that were statistically different from each other were compared using Duncan's multiple range tests at 5% confidence interval. Standard deviations were calculated using the same software.
Analytical results The approximate composition (dry-weight basis) of QF used in this study was 14.57 ± 0.37% crude protein, 2.99 ± 0.19% ash, 4.86 ± 0.18% crude fat and 3.21 ± 0.15% crude fiber. Besides, L*, a* and b* values of quinoa flour were 88.55 ± 0.22, 0.48 ± 0.03 and 13.04 ± 0.47 respectively. Literature knowledge on chemical composition and color values of QF confirmed our results (Alvarez-Jubete et al., 2009; Alvarez-Jubete et al., 2010a; Tömösközi et al., 2011).
Analysis of tarhana samplesFermentation loss Fermentation loss values are summarized in Table 2. As seen in Table 2, high QF addition level (60%) to tarhana formulation decreased the fermentation loss values of the tarhana samples. The tarhana containing the lowest quinoa flour (40% QF) had the fermentation loss values above the values of other formulation, and this was followed by the 50% QF (19.84 ± 0.52%) and 60% QF (16.89 ± 0.48%). The highest fermentation loss values were determined for tarhana made with 40% QF addition level (22.24 ± 0.26%). These results show that QF addition levels influenced on fermentation loss values of tarhana samples.
| 40% QF2 | 50% QF2 | 60% QF2 | ||
|---|---|---|---|---|
| Fermentation loss (%) | 22.24 ± 0.26a | 19.84 ± 0.52b | 16.89 ± 0.48c | |
| Crude protein (%) | 16.26 ± 0.08c | 16.60 ± 0.09b | 16.99 ± 0.06a | |
| Ash (%) | 3.01 ± 0.09b | 3.20 ± 0.07ab | 3.41 ± 0.06a | |
| Crude fat (%) | 7.64 ± 0.09c | 8.13 ± 0.13b | 8.72 ± 0.20a | |
| Colour values | L* | 77.74 ± 0.28a | 76.47 ± 0.11b | 74.92 ± 0.05c |
| a* | 7.60 ± 0.14c | 9.03 ± 0.27b | 10.28 ± 0.22a | |
| b* | 36.52 ± 0.38a | 33.98 ± 0.21b | 32.29 ± 0.41c | |
| Minerals (mg/100g) | K | 882.12 ± 5.64c | 940.62 ± 8.56b | 1012.31 ± 7.41a |
| Mg | 95.41 ± 3.20c | 110.67 ± 3.27b | 145.37 ± 2.56a | |
| Ca | 172.37 ± 2.02c | 184.78 ± 3.44b | 201.36 ± 3.71a | |
| Fe | 4.89 ± 0.13b | 5.16 ± 0.11ab | 5.29 ± 0.10a | |
| Zn | 2.21 ± 0.04a | 2.23 ± 0.08a | 2.28 ± 0.03a |
Optimal fermentation is essential in functional and sensory properties of tarhana for consumer acceptability. Over fermentation causes not only a decrease in functionality, but also a loss in dry matter up to 25% (Türker and Elgün, 1995) which is of great commercial importance. Long fermentation process (72 h) during tarhana preparation by lactic acid bacteria and baker's yeast was responsible for fermentation losses (Bilgiçli and Elgün, 2005; Bilgiçli, 2009a).
Colour values Table 2 shows the changes in the colour values (L*, a* and b*) of the tarhana samples. According to the Table 2, the L* values of tarhana samples ranged from 74.92 ± 0.05 to 77.74 ± 0.28. Brightness (L*) values of tarhana samples declined after the high quinoa flour addition. Redness (a*) and yellowness (b*) values of gluten-free tarhana samples produced from 40% QF addition level were determined as 7.60 ± 0.14 and 36.52 ± 0.04, respectively; while these values were 9.03 ± 0.27 and 33.98 ± 0.21 produced from 50% QF, 10.28 ± 0.22 and 32.29 ± 0.41 60% QF addition level. The tarhana samples containing 60% QF had the highest a* values, while tarhana samples containing 40% QF had the highest b* values. As expected, QF affected the colour of gluten-free tarhana samples. Its reason could be due to colour intensity of the raw material, browning reaction, and high phytic acid content. Bilgiçli (2009a) reported phytic acid degraded during fermentation of tarhana, so free mineral content of tarhana increased. Then, these free minerals catalyzed some non-enzymatic browning reactions. Valencia-Chamorro (2003) reported that phytic acid is located in the external layers as well as in the endosperme and the average phytic acid concentration was 1.18 g/100 g in varieties of quinoa.
Chemical compositions Crude protein, ash and crude fat content of the tarhana samples ranged between 16.26 – 16.99%, 3.01 – 3.41% and 7.64 – 8.72%, respectively (Table 2). The highest crude protein, ash, and crude fat contents were obtained with 60% QF addition level. This was an expected result, because QF is a very nutrient rich product. In a study of Alvarez-Jubate (2009) quinoa seeds was reported to contain 14.5% protein, 5.2% fat, 64.2% total starch, 14.2% dietary fiber and 2.7% ash. According to Table 2, the crude protein, ash and crude fat content of tarhana samples increased significantly (P < 0.05) with QF addition level. The crude protein content of tarhana samples produced from 40% QF addition level were lower than the other gluten-free tarhana samples, and crude protein content of the tarhana increased when QF were used instead of rice flour and potato starch. Protein content in quinoa is generally higher than in common cereals such as wheat (Koziol, 1992; Alvarez-Jubate et al., 2010a). Ash values also increased when QF incorporated to the tarhana samples. High QF addition level (60%) to tarhana formulation increased the ash content of the tarhana samples when compared with the other QF addition levels. The lowest ash values were determined in the tarhana samples made with 40% QF. QF increased the crude fat content of gluten-free tarhana samples above 40% addition level from 7.64 ± 0.09% up to 8.72 ± 0.20%. Bilgiçli (2009b) found that the ash, protein and fat content of gluten-free tarhana samples, produced from 60% buckwheat flour + 20% corn starch + 20% rice flour, were 2.29%, 15.0% and 7.2%, respectively.
Mineral contents Mineral contents of the tarhana samples are given in Table 2. All of the investigated minerals in tarhana samples increased with QF addition level except Zn content. QF addition levels showed a significant effect on total K, Mg, Ca and Fe contents. Zn mineral contents were not significantly (P > 0.05) affected by QF addition levels. Tarhana samples containing 40% QF had the lowest values of K, Mg, Ca and Fe minerals. According to the tarhana samples containing 40% QF, K, Mg, Ca and Fe contents (mg/100 g) increased from 882.12 ± 5.64, 95.41 ± 3.20, 172.37 ± 2.02 and 4.89 ± 0.13 to 940.62 ± 8.56, 110.67 ± 3.27, 184.78 ± 3.44 and 5.16 ± 0.11 in tarhana samples containing 50% QF, respectively. The tarhana samples prepared with 60% QF contained the highest levels of K (1012.31 ± 7.41 mg/100 g), Mg (145.37 ± 2.56 mg/100 g), Ca (201.36 ± 3.71 mg/100 g) and Fe (5.29 ± 0.10 mg/100 g) minerals. The Recommended Dietary Allowances (RDAs) for children (4 – 8 years) are 800 mg of calcium, 10 mg of iron, 3.8 g of potassium, 130 mg of magnesium, and 5 mg of zinc. When 100-g (dry matter) tarhana containing 60% QF were consumed 25.2% of RDA for Ca, 52.9% of RDA for Fe, 26.6% of RDA for K, 100% RDA for Mg and 45.6% of RDA for Zn were taken by the children body. These RDA ratios were 21.5% of Ca, 48.9% of Fe, 23.2% of K, 73.4% Mg and 44.2% of Zn in the tarhana samples made with 40% QF. This was an expected result. Because, quinoa is a very rich source of minerals. It contains more calcium, magnesium, iron, and zinc than common cereals, and the iron content is particularly high (Jancurová et al., 2009).
Sensory properties The scores of sensory properties of tarhana soups made with different ratios of quinoa flour are shown in Fig. 1. It can be seen in Fig. 1, QF affected the scores of sensory properties of gluten-free tarhana soups. QF addition level had statistically significant effect at P < 0.05 on taste, colour, odor, consistency, sourness and overall acceptability. According to the results, tarhana soups made of 40% QF + 30% rice flour + 30% potato starch mixtures had lower scores in terms of taste and odor. Also, tarhana with added 40% QF had a significantly lower overall acceptability score than the other formulations. Addition of QF increased taste, odor and sourness. Colour values of tarhana with added 50% QF were more highly accepted than the other two tarhana samples. The tarhana soups containing 50% QF addition level had the highest scores for consistency and overall acceptability.
Sensory properties of gluten-free tarhana samples. 40% QF: 40% quinoa flour + 30% rice flour + 30% potato starch; 50% QF: 50% quinoa flour + 25% rice flour + 25% potato starch; 60% QF: 60% quinoa flour + 20% rice flour + 20% potato starch.
Several recent studies have showed the successful formulation of pseudocereal-containing gluten-free cereal based products. In this study, the use of QF which is a pseudocereal in tarhana was investigated. QF was successfully incorporated into gluten-free tarhana formulation. High QF addition levels increased the ash, crude protein, crude fat and mineral (K, Mg, Ca, and Fe) contents of tarhana samples. Also, sensory properties of the tarhana samples were developed the addition of QF. As a conclusion, a new gluten-free product was developed by QF; it is advisable QF + rice flour + potato starch combination instead of wheat flour in gluten-free tarhana. The mentioned combination may be a solution for the individuals suffering from celiac disease.
