Quality Assurance and Safety of Crops & Foods
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Wageningen Academic Quality Assurance and Safety of Crops & Foods, 2015; 7 (3): 321-326 Publishers The assessment of leavened and unleavened flat breads properties enriched with wheat germ H. Levent1, N. Bilgiçli2* and N. Ertaş2 1Mersin University, Mut Vocational School of Higher Education, University Street 69, 33600 Mersin, Turkey; 2Necmettin Erbakan University, Faculty of Engineering and Architecture, Department of Food Engineering, Dr. Hulusi Baybal Street 12, 42060 Konya, Turkey; [email protected] Received: 16 September 2013 / Accepted: 10 January 2014 © 2014 Wageningen Academic Publishers RESEARCH ARTICLE Abstract Wheat germ is a good source of protein, minerals, vitamins, phytochemicals and dietary fibre. In this study, coarse wheat germ (CWG) and fine wheat germ (FWG) were used in the formulations of leavened flat bread (bazlama) and unleavened flat bread (yufka) at three different ratios (10, 20 and 30%). Some physical, chemical and sensory properties of both flat breads were determined. Surface colour of flat breads containing CWG/FWG became darker, more reddish and yellowish compared to control breads. The ash, protein and fat content of flat breads improved with increasing amount of CWG/FWG in flat bread formulation. A significant (P<0.05) increase was also obtained in Fe, K, P and Zn contents of the flat breads in all usage levels of CWG/FWG. As a result of sensory evaluation, leavened flat breads containing CWG had higher overall acceptability scores than leavened flat breads prepared with FWG. CWG usage over 20% level in leavened flat bread and over 10% level in unleavened flat bread caused a decrement in overall acceptability scores of flat breads. Keywords: wheat germ, flat bread, bazlama, yufka 1. Introduction Breads are the staple foods in diets of people in Turkey. The main ingredient of bread is generally refined wheat flour Wheat germ (WG) constitutes 3.0% of whole grain and which is rich in carbohydrate. Breads are important vehicle is obtained as by-product of the flour milling industry. for nutritional enrichment. For adequate and balanced WG proteins provide high nutritive value comparable to nutrition of school-going children and adults it can be animal proteins. It has significant quantity of essential produce with high nutritive value with supplementation amino acids especially lysine which is deficient in many of different ingredients containing high amount of protein, cereals (Ge et al., 2000; Rao et al., 1980a). WG is also a rich mineral, fibre and vitamin. Bazlama, lavash, yufka and pide source of vitamins, minerals, unsaturated fatty acids, free are widely produced traditional leavened and unleavened sugars and functional phytochemicals including ferulic acid, flat bread types of Turkey. Bazlama can be defined as phytic acid, glutathione and phytosterols (Al-Hooti et al., leavened flat bread (LFB) with a creamish yellow colour. 2002; Kevin, 1995; Sidhu et al., 2007). WG provides three It has a circular shape with an average thickness of 3 cm times as much protein, seven times as much fat, six times and a diameter ranging from 10 to 20 cm (Başman and as much mineral contents compared to wheat flour (Rao Köksel, 1999). Yufka is unleavened flat bread (UNFB) with et al., 1980b). WG has good potential for increasing the 1-2 mm thickness and 40-50 cm diameters (Başman and nutritional status of many foods such as bread, macaroni, Köksel, 2001). Yufka have lower thickness, higher surface cookie, and tarhana, due to the rich composition of WG area, lower moisture content and longer shelf life than (Arshad et al. 2007; Bajaj et al., 1991; Gómez et al., 2012; bazlama. Generally, bazlama and yufka are produced from Pınarlı et al., 2004; Sidhu et al., 1999). refined white wheat flour in Turkey. In rural areas of Turkey, ISSN 1757-837X online, DOI 10.3920/QAS2013.0341 321 H. Levent et al. wheat flour with high extraction ratio is preferred in the plate heated by electrical resistances, 1,500 W). For UNFB production of these flat breads. samples, mixed dough was fermented at 30 °C for 30 min and then dough was divided into 4 pieces and rounded Some laboratory studies have been conducted for into a ball shape. The dough balls were rolled to the final enrichment of Turkish flat breads. For these purpose barley possible thickness and baked at a temperature of 280±5 °C flour and wheat bran (Başman and Köksel, 1999, 2001), on a sac for 1 min. After cooling at room conditions for triticale flour (Coşkuner and Karababa, 2005), resistant 1 h, physical and sensory analyses were performed and starch (Levent et al., 2012), dairy by-products (Madenci the remaining bread samples were stored in plastic bags et al., 2012), legume flours (Levent and Bilgiçli, 2012a), for chemical analyses. lupin, buckwheat and oat flours (Levent and Bilgiçli, 2012b; Yıldız and Bilgiçli, 2012) have been used in Turkish LFB Physical measurements and UNFB production. Diameter and thickness of LFB and UNFB samples were The objectives of this research were to increase the determined according to Yıldız and Bilgiçli (2012). The nutritional profile of flat breads by usage of WG with two spread ratio values of samples were found by dividing particle size and to evaluate the influence of WG level on diameter to thickness value of flat breads. Minolta CR-400 physical, chemical and sensory quality of LFB and UNFB. (Konica Minolta Sensing, Inc., Osaka, Japan) chromameter was used to record the L* (lightness/darkness), a* (redness/ 2. Materials and methods greenness), and b* (yellowness/blueness) colour parameters of flat breads. The saturation index (SI) was calculated as: Materials SI = (a*2 + b*2)1/2 The wheat flour which was used in flat bread production was commercial flour with a crude protein and ash content Chemical analyses of 11.85 and 0.51%, respectively. WG was obtained from a flour mill in Konya, Turkey. The stabilisation of WG was Samples were analysed for their moisture, ash, protein performed by microwave heating in home-type rotating and fat content using approved methods of American microwave oven (2,450 Hz, 700 W; Arçelik, Istanbul, Association of Cereal Chemists (AACC, 1990). For Turkey) for 5 min according to our previous study (Levent mineral analysis, 0.3 g dried sample was put into burning and Bilgiçli, 2013). Stabilised WG was ground with coffee cup and 10 ml HNO3+H2SO4 were added. The samples grinder. Coarse (750-500 µm) wheat germ (CWG) and fine were incinerated in a microwave oven (MARS 5; CEM (500-250 µm) wheat germ (FWG) was obtained by using Corporation, Matthews, NC, USA). The solution was 250, 500 and 750 µm sieves (Imaş makine, Konya, Turkey). diluted with distilled water to 100 ml. Concentrations were determined by inductively coupled plasma atomic emission Preparation of leavened and unleavened flat bread spectrometer (Vista series; Varian International AG, Zug, samples Switzerland) (Bubert and Hagenah, 1987). LFB and UNFB samples were prepared according to the Sensory analyses method given by Akbaş (2000) and Başman and Köksel (2001), respectively. For preparation of control LFB, wheat The sensory evaluation of LFB and UNFB samples flour (200 g, 14% moisture basis), salt (3 g), sugar (2 g), fresh containing CWG and FWG was conducted with 22 yeast (5 g) and water, and for preparation of control UNFB, panellists (age range of 27 to 50). Flat bread samples were wheat flour (200 g, 14% moisture basis), salt (3 g) and water presented in a random order to each panellist separately were used as ingredients. For preparation of LFB/UNFB on the same day. The panellists were asked the score for containing WG, wheat flour replaced with CWG or FWG appearance, shape and symmetry, texture, mouthfeel, taste- at 10, 20 and 30% levels in flat bread formulation. All odour and overall acceptability of LFB and for appearance, ingredients and water (according to farinogram absorption elasticity, mouthfeel, taste-odour and overall acceptability value) were mixed in a Hobart mixer (Hobart N50; Canada of UNFB samples on a 9 points scale were: 1 = dislike Instruments, North York, Ontario, Canada) for optimum extremely, 2 = dislike very much, 3 = dislike moderately, dough development for both LFB and UNFB samples. After 4 = dislike slightly, 5 = neither like nor dislike, 6 = like mixing, the dough was allowed to ferment at 30 °C for 1 h slightly, 7 = like moderately, 8 = like very much, and 9 = and divided into two equal pieces and rounded into a ball like extremely. shape and allowed to rest for 6 min at room conditions for LFB preparation. After that, dough was sheeted to final thickness of 10 mm by using stainless steel circle of 17 cm diameter and baked at 280±5 °C for 5 min on sac (metal 322 Quality Assurance and Safety of Crops & Foods 7 (3) Effect of wheat germ on bread properties Statistical analyses According to particle size variance source, FWG usage in UNFB gave higher diameter and spread ratio compared to Data were subjected to analyses of variance (ANOVA) CWG usage. FWG could have less detrimental effect on with two factors: WG particle size (coarse/fine) and WG gluten network of dough due to smaller particle size than replacement level (0, 10, 20 and 30%). The analysis of CWG. High level of CWG/FWG (20-30%) usage in flat variance (ANOVA) was performed using the Statistical bread formulation gave higher diameter and spread ratio software JMP 5.0.1 (SAS Institute, Cary, NC, USA). The in UNFB compared to control UNFB without WG. comparison of the means was made by using Student’s t-test. Significant differences were based on P<0.05. The colour values of LFB and UNFB samples are given in Table 2. Particle size of the WG affected the b* and SI 3.