INTRODUCTION

The increase in demand for fast food in a bid to save time and meet up with secular pressures among women in many developing countries have contributed to the rate at which snack such as cookies and biscuits are included in family menu. Composite flour produced from cereals and legumes possess the advantage of improving the overall nutrition according to Food and Agricultural Organization (FAO, 1995). The crop, seed or peel to be employed in composite flour blends should be readily available, acceptable culturally and possess increased nutritional potentials (Akobundu et al., 2008).

Pumpkins are grown all round the world for a variety of reasons ranging from agricultural purposes to commercial and ornamental (Wolford and Banks, 2008). Pumpkin (Cucurbita spp.) locally referred to as ‘elegede’ in South West Nigeria is cultivated in various parts of the country as a traditional vegetable crop. The leaves are usually prepared as vegetable soup, the pulp are boiled or fried, while the seed are either, roasted, baked or added to stew to eat yam. It is estimated that pumpkin seeds constitute 2.9% in weight of the fresh fruit and 32% of the weight in the dry form. The seed kernels have been used as additives in some dishes, and there are reports on the nutritional value of pumpkin seed kernel proteins (25.4%-35. %) and oils (41.5%-49.1%) (Norfezah et al., 2011; Rodr´ıguez- Miranda et al., 2014). Pumpkin seeds have also been reported to exhibit several heath benefits including anti-diabetic, anti-hypertensive, anti- tumor, anti-bacterial, anti-hypercholesterolemic and anti-inflammatory actions (Rado˘caj et al., 2012).

A number of studies have reported improved nutritive values of cookies by incorporating, soy protein and fibre (Shrestha and Noomhorm, 2002), chickpea, lentil (Zucco et al., 2011), soybean and maize (Mishra et al., 2012), germinated sesame (Olagunju and Ifesan, 2013), barley (Sharma and Gujral, 2014), mango kernel (Ifesan, 2017) and watermelon seed (Ifesan and Ebosele, 2017) into wheat flour. The use of composite flour as substitute in baking industry will in some way preserve the economy of developing countries. Application of locally sourced and nutritious raw materials for product development has been widely accepted. In addition, the quest for healthy and functional foods has necessitated research into locally available food sources. There is need therefore to investigate the nutritional composition and acceptability of cookies made from blends of wheat and pumpkin seed flour.

MATERIALS AND METHODS

Materials

Wheat flour, sugar, margarine, powdered milk, salt, sodium bicarbonate and vanilla flavor used for this study were bought from Oba market in Akure, Ondo State while the pumpkin fruits were purchased from Owena market in Osun State, Nigeria.

Preparation of pumpkin seed flour

Mature pumpkin fruits were washed, cut into small sizes and then cooked for 45 min. They were allowed to cool down for easy separation of the pulp from the seed. The seeds were then oven dried at 60 °C for 4 hour, milled to obtain pumpkin seed flour and packaged in air tight polythene bag.

Formulation of wheat-pumpkin seed flour for cookies production

Blends with different proportions of wheat flour and pumpkin seed flour were prepared while 100% wheat flour served as control (Table 1). A digital weighing balance (Model: FA2004) and Philips blender (HR 1702) were used for weighing and mixing of the flour, respectively.

Table 1. Formulation for the wheat-pumpkin seed flour for cookies production

WF= wheat flour; PSF=pumpkin seed flour

Cookies were produced as described by Olagunju and Ifesan (2013) with slight modifications. All the ingredients (sugar, margarine, powdered milk, salt, sodium bicarbonate and vanilla flavor) were appropriately weighed and mixed thoroughly in a Kenwood mixer. The content was transferred into the mixing bowl while wheat flour or wheat-pumpkin seed flour and sodium bicarbonate were added with continuous mixing for 15 minutes until smooth dough was obtained. A piece of this dough was cut, placed on a clean table then rolled out using rolling pin until the desired uniform texture and thickness of 0.44 cm was obtained. Biscuit cutter was then used to cut the sheet of the dough into required shapes and sizes and placed on the baking tray already greased with margarine. The baking was done at 200 ºC for 20 minutes. After baking, the hot cookies were placed on clean trays to cool down. The cookies were then packed into polyethylene sachet and sealed prior to further analyses.

Determination of proximate composition of wheat, wheat-pumpkin seed cookies

Crude protein, lipid, crude fibre, moisture and ash content were determined in accordance with the standard methods of Association of Official Analytical Chemist (AOAC, 2012). Carbohydrate was determined by difference.

Determination of mineral content of cookies from wheat and wheat-pumpkin seed flour

Mineral composition of cookies was determined following the dry ashing technique (AOAC, 2012).

Preparation of wheat, wheat-pumpkin seed cookies extract

Aqueous extract of cookies was prepared using the method described by Oboh et al. (2010). About 2.5 g of the ground cookies was soaked in 100 ml of distilled water at 37 ^oC for about 24 hours. It was then filtered, centrifuged at 2,000 rpm for 10 min and supernatant was stored in the refrigerator for further analyses.

Determination of total flavonoid content of cookies extract

About 0.2 ml of the extract was added to 0.3 ml of 5% NaNO₃ at zero time. After 5 minutes, 0.6 ml of 10% AlCl₃ was added and after 6 minutes, 2 ml of 1 M NaOH was added to the mixture followed by the addition of 2.1 ml of distilled water. Absorbance was read at 510 nm against the reagent blank and flavonoid content was expressed as mg rutin equivalent (Bao, 2005).

Determination of DPPH free radical scavenging ability of cookies extract

The free radical scavenging ability of cookies extract against DPPH (1,1-diphenyl-2 picrylhydrazyl) radical was evaluated (Gyamfi et al., 1999). About 1 ml extract was mixed with 1 ml of 0.4 mM/l methanol solution containing DPPH radicals. The mixture was left in the dark for 30 minutes and the absorbance was measured at 516 nm using the spectrophotometer. The DPPH free radical scavenging ability was calculated with respect to the reference, which contained all the reagents without the test sample.

Determination of phytochemical content of wheat and wheat-pumpkin seed cookies

Oxalate determination

One gram of sample was weighed into a conical flask and 75 ml of 3 M H₂SO₄ was added. The solution was placed on a magnetic stirrer for about 1h, and then filtered using Whatman No. 1 filter paper. About 25 ml of sample filtrate was collected and titrated hot (80- 90ºC) against 0.1M KMNO₄ solution to the point when a faint pink colour appeared that persisted for at least 30 seconds (Day and Underwood, 1986).

Phytate determination

Phytate was determined according to the method of Wheeler and Ferrel (1971). Four gram of each sample was soaked in 100 ml of 2 % HCl for 3 hours and then filtered through a No 1 Whatman filter paper. About 25 ml was taking out of the filtrate and placed inside a conical flask and 5ml of 0.3 % of ammonium thiocyanate solution was added as indicator while 53.5ml of distilled water was added to give the proper acidity and then titrated against 0.00566 g per ml of standard iron (lll) chloride solution that contained about 0.00195 g of iron per milliliter until a brownish yellow colour was observed.

Determination of saponin

The spectrophotometric method of Brunner (1984) was used for saponin determination. About 2 g of the finely ground cookies was weighed and 100 ml of Isobutyl alcohol was added. The mixture was placed on a shaker for 5 hours to ensure uniform mixing. The mixture was filtered with No 1 Whatman filter paper into a beaker containing 20 ml of 40% saturated solution of magnesium carbonate. The mixture obtained was again filtered though No 1 Whatman filter paper to obtain a clean colourless solution. One mililitre of the colourless solution was taken into volumetric flask while 2 ml of 5% iron (III) chloride solution was added and made up to mark with distilled water. It was allowed to stand for 30 min for the colour to develop. The absorbance was read against the blank at 380 nm.

Determination of sensory attributes of wheat-pumpkin seed cookies

Quality attributes of cookies made from wheat flour and wheat-pumpkin seed flour was assessed by 20 member sensory panelists. The panelists were supplied with a form and asked to score the cookies using the 9 point Hedonic scale with respect to colour, taste, flavour, appearance, crumb texture and overall acceptability (Solomakos et al., 2008).

Statistical Analysis.

All data collected was subjected to Analysis of Variance (ANOVA) using SPSS (version 16). Duncan New Multiple Range Test (DNMRT) was used to separate the differences in the mean scores.

RESULTS AND DISCUSSION

Proximate composition of cookies

Table 1 showed the proximate composition of cookies made from wheat and wheat-pumpkin seed flour blends. Moisture content ranged from 3.05% to 4.95%. Moisture and water activity of food product dictates greatly the keeping quality of the food (Ajani et al., 2012). The values obtained from this study are lower than those reported by Chauhan et al. (2016) for wheat- amaranth cookies. It was observed that the moisture content reduced with increase in pumpkin seed flour substitution while the dry matter content increased gradually. This is similar to what was observed when soybean was added to cowpea (Ogundele et al., 2014). The reduction in the moisture content of cookies may be due to the increase in protein content as a result of the addition of pumpkin seed flour. Protein has been reported to possess certain functional attributes which include; water sorption, viscosity, elasticity, foamability, foam stability and fibre formation (Sunful et al., 2010).

Table 2. Proximate composition (%) of cookies made from wheat flour and wheat-pumpkin seed flour

Means with different letters are significantly different in the same column at the p≤0.05

WF=wheat flour; PSF=pumpkin seed flour

Protein content of cookies made from wheat-pumpkin seed flour ranged from 17.95% -21.02% and was found to increase with increase in addition of pumpkin seed flour. The protein content of pumkin seed flour (38.68%) is greater than that of wheat flour (17.95%). The result in this study is similar to the findings of Dixit et al. (2011) who reported an increase in protein content of akara with substitution of soybean, higher than that of wheat-mango kernel cookies (9.74%-11.93%) (Ifesan, 2017), and lower than that of wheat-watermelon seed cookies (21.00%- 33.25%) (Ifesan and Ebosele, 2017). The protein content of wheat-pumpkin seed cookies is higher than the 10% which was the minimum value recommended by Food Agriculture Organization/World Health Organization as reported by Ojinnaka et al. (2016). The ash content of a food material could be used as an index of its mineral constituent. It was observed that the ash content of cookies (2.48%-2.96%) increased with increase in pumpkin seed flour substitution. The same observation was made by Banu et al. (2012) who reported that addition of wheat bran to dough meal increased the ash content. Fat content of wheat and wheat-pumpkin cookies ranged from 23.08%-27.33% and the result of the fat content of cookies followed the same trend with ash and protein content. Similar observations were made when African walnut was employed as composite flour in cookies production and there was increase in the fat content of cookies (Ndie et al., 2010; Ekwe and Ihemeje, 2013). Due to high fat content of pumpkin flour, it should be used shortly after production to prevent rancidity which can lead to deterioration of food product (Ikujenlola, 2014). It was observed that the fibre content of wheat flour (2.20%) and pumpkin flour (0.44%) yielded fibre content of 2.41%-2.64% in wheat-pumpkin cookies. The carbohydrate content of cookies ranged from 43.22% to 49.22% and the values decreased significantly with increase in addition of pumpkin flour. A decrease in carbohydrate content of cake with increasing substitution of African bread fruit flour was reported (Ihediohanma et al., 2009).

Mineral content of wheat-pumpkin cookies

The mineral content of wheat-pumpkin cookies generally increased with increase in pumpkin content (Table 2). The sodium content of the cookies ranged from 56.11 mg/100g -91.20 mg/100g, calcim (7.19 mg/100g-63.28 mg/100g), phosphorus (53.48 mg/100g-189.43 mg/100g), magnesium (6.81 mg/100g-8.22 mg/100g), zinc (0.41 mg/100g-1.06 mg/100g) and iron (2.78 mg/100g-2.81 mg/100g). The calcium content of the cookies were found to increase appreciably with increase in pumpkin seed flour from 7.13 mg/100g in control to 63.28 mg/100g in sample with 80% wheat+20% pumpkin seed flour. The values obtained from this study are higher than those reported by Fasasi and Alokun (2013) for maize snack enriched with soy flour. Calcium is an important mineral needed for bone formation and neurological functions of the body. The values obtained may be an indication that composite flour from pumpkin seed employed for cookies production are good sources of minerals than wheat flour. Pumpkin fruit has a good content of β-carotene content with moderate content of carbohydrates, vitamins and minerals (Yadhav et al., 2010).

Table 2. Mineral composition (mg/100g) of wheat and wheat-pumpkin seed cookies

Means with different letters are significantly different in the same column at the p≤0.05 level.

WF=wheat flour; PSF=pumpkin seed flour; ND=not detected

Physical Properties of wheat-pumpkin seed cookies

It was observed that there were fluctuations in all the values obtained for the physical properties of wheat-pumpkin seed cookies (Table 3). The control sample had a weight (3.04 g) that is lower than those of wheat-pumpkin cookies (3.27 g-3.84 g). The low weight of the samples may suggest ease of packaging of the cookies. The diameter of wheat biscuit was 29.86 mm while those of wheat-pumpkin cookies ranged from (22.06 mm-31.33 mm). The thickness of the control sample (7.33 mm) was found to be lower compared to wheat-pumpkin seed cookies (8.13 mm-11.15 mm). The increase in thickness of cookies could be due to the binding and swelling of the flour components as a result of water absorption (Sengev et al., 2015). This is consistent with the findings of Chinma and Gernah (2007) who reported a similar observation when wheat was substituted with cassava, soybean and mango kernel flour. Cookies prepared from wheat flour had lower spread ratio (0.24) compared to the cookies made from wheat-pumpkin seed flour blends (0.26-0.36). This is similar to observations from wheat-mango kernel cookies (Ifesan, 2017) and wheat-watermelon cookies (Ifesan and Ebosele, 2017). It however disagreed with the findings of Adeyeye (2016) who reported the highest value for wheat flour during cookies production from blends of wheat and sorghum flour. The differences recorded might be due to nature of starch in the composite flour (Mir et al., 2015).

Table 3. Physical Properties of Cookies from Wheat and Pumpkin Seed Flour Blends

Means with different letters are significantly different in the same column at the p≤0.05 level.

WF= wheat flour; PSF=pumpkin seed flour

Phytochemical content of wheat and wheat-pumpkin cookies

Results of the phytochemical properties of wheat and wheat-pumpkin seed cookies were found to increase with addition of the composite flour. The tannin content for control was 0.14 mg/100g while it increased from 0.15 mg100g – 0.19 mg/100g for cookies with pumpkin seed flour. Phytate content was 32.14 mg/100g for wheat cookies and 38.73 mg/100g-53.56 mg/100g for wheat-pumpkin seed cookies. Saponin in the cookies ranged from 15.20 mg/100g in control to 22.50 mg/100g in cookies with composite flour. The increases observed in the phytochemicals of cookies with addition of pumpkin seed is an indication that pumpkin seed flour is rich in phytochemical and may further be investigated as a functional flour.

Table 4. Phytochemical composition (mg/100g) of cookies from blends of wheat and pumpkin flour

Means with different letters are significantly different in the same column at the p≤0.05 level.

WF= wheat flour; PSF=pumpkin seed flour

Antioxidant properties of wheat-pumpkin seed cookies

Antioxidants are compounds that inhibit or delay the oxidation of other molecules by inhibiting the initiation or propagation of oxidizing chain reactions. They are compounds when added to food products, especially to lipids and lipid-containing foods, can extend the shelf-life by retarding the process of lipid peroxidation, which is one of the major reasons for deterioration of food products during processing and storage (Mala and Kurian, 2016). Table 5 showed that the flavonoid content of cookies ranged from 0.01 mg/100g to 0.14 mg/100g. There was no significant difference in the samples except for cookies produced from 95% wheat flour; 5% pumpkin flour blend which had the highest value. The ability of wheat-pumpkin seed cookies to scavenge free radicals revealed that the control (10.84 mg/g) had the highest value and the DPPH values decreased with increase in addition of pumpkin seed (6.17 mg/100g-5.03 mg/100g).

Table 5. Antioxidants properties of wheat-pumpkin Cookies (mg/100g)

Means with different letters are significantly different in the same column at the p≤0.05 level.

WF= wheat flour; PSF=pumpkin seed flour.

Consumer acceptability of wheat-pumpkin seed cookies

Table 6 showed the sensory attributes of cookies made from pumpkin seed and wheat flour. The panelist scored the cookies on appearance (7.11-8.00), colour (7.05-8.16), texture (7.38-8.05), taste (7.38-8.16) and overall acceptability (7.27-7.83). It was observed that cookies made from 95% wheat: 5% pumpkin seed was rated higher and preferred than the control sample with 100% wheat in all the sensory attributes. The overall acceptability score for all the samples showed that cookies from wheat-pumpkin seed were well accepted and could compete with cookies made from 100% wheat flour.

CONCLUSION

The result of this study revealed that cookies of high nutritional content could be produced from blends of wheat-pumpkin seed flour. Cookies produced from 100% wheat flour and composite flour cookies had the same acceptability score. Increasing the utilization of pumpkin seed flour to fortify wheat flour will increase the nutritional quality of products and reduce dependence on wheat as the sole source of flour.

Table 6. Sensory Evaluation of Cookies from blends of pumpkin seed and wheat flour

Means with different letters are significantly different in the same column at the p≤0.05 level.

WF= wheat flour; PSF=pumpkin seed flour

REFERENCES

1. Adeyeye, S.A.O. (2016). Assessment of quality and sensory properties of sorghum–wheat flour cookies. Cogent Food Agric. 2: 1245059.

2. Ajani, A., O., Oshundahunsi, O.F., Akinoso, R., Arowora, K. A., Abiodun, A.A., & Pessu, P. O. (2012). Proximate Composition and Sensory Qualities of Snacks Produced from Breadfruit Flour. Global J. Sc. Fron. Res. Biol. Sci. 12, 2249-4626.

3. AKOBUNDU, E. T., Ubbaonu, C. N., & Ndupuh, C. E. (1988). Studies on the baking potential of non-wheat composite flours. Journal of food science and technology (Mysore), 25(4), 211-214.

4. AOAC. (2012). Association of Official Analytical Chemist. Official Methods of Analysis of the Analytical Chemist International, 18^th ed. Gathersburg, MD USA.

5. Banu, J., Stoenescu, G., Ionescu, V.S., & Aprodu1, J. (2012). Effect of the addition of wheat bran stream on dough rheology and bread quality. Annals of the University Dunarea de Jos of Galati Food Tech. 36, 39-52.

6. Bao, J. Y., Cai, M., Sun, G., Wang, & Corke, H. (2005). Anthocyanins, Flavonoid and Free Radical Scavenging Activity of thines Baybery (Myrial rubia) extracts and their colour properties and stability. J. Agric Food Chem. 53: 2327-2332.

7. Brunner, J.H. (1984). Direct spectrophotometer determination of saponin. Anal. Chem. 34, 1314- 1326.

8. Chauhan, A., Saxena, D.C., & Sukhcharn, S. (2016). Physical, textural, and sensory characteristics of wheat and amaranth flour blend cookies. Cogent Food Agric. 2, 1-8.

9. Chinma, C. E., & Gernah, D. I. (2007). Physical and sensory properties of cookies produced from cassava/soybean/mango composite flours. J. Food Tech. 5, 256–260.

10. Day, R.A. (Jnr) &Underwood, A.L. (1986): Quantitative Analysis. 5^thedn.Prentice – Hall Publication. pp 701.

11. Dixit, A. K., Antony, J. I. X., Sharma, N. K., & Tiwari, R. K. (2011): Soybean constituent and their functional benefits. In: Tiwari VK, Mishra BB (Eds) Opportunity, challenge and scope of natural products in medicinal chemistry, Research signpost Publication, Kerala, India pp. 367–383.

12. Ekwe, C.C., & Ihemeje, A. (2013). Evaluation of physicochemical properties and preservation of African walnut (Tetracarpidium conophorum). Acad. Res. Int 4(6): 501 – 512.

13. Fasasi O. S., & Alokun O. A. (2013). Physicochemical properties, vitamins, antioxidant activities and amino acid composition of ginger spiced maize snack “kokoro” enriched with soy flour (a Nigeria based snack). J. Agric. Sci. 5, 73-77.

14. Food and Agriculture Organization. (1995). Sorghum and Millet in Human Nutrition. Food and Agriculture Organization of the United Nations, Food and Nutrition series No 27, Rome.

15. Gyamfi, M.A., Yonamine, M., & Aaniya, Y. (1999). Free radical scavenging action of medicinal herbs from Ghana: thonningia sanguine on experimentally induced liver injuries. Gen. Pharm 32, 661–667.

16. Ifesan, B.O.T. (2017). Chemical Properties of mango kernel and seed and production of biscuit from wheat-mango kernel flour blends. Int. J. Food Nutr. Res. 2017: 1:5.

17. Ifesan, B.O.T., & Ebosele, F. (2017). Chemical properties of watermelon seed and the utilization of dehulled seed in cookies production. Carpathian J. Food Sci. Tech. 9, 126-135.

18. Ihediohanma, N. C., Durunma, A. I., & Onuegbu, N.C. (2009). Functional properties and performance of Alum treated African Breadfruit (Treculia africana) as a composite flour in cake production. Nig Food J. 27, 159-167.

19. Ikujenlola, A.V. (2014). Chemical and functional properties of Complementary food blends from malted and unmalted Acha (Digitariaexilis), Soybean (Glycine, max) and deffated Sesame ( Sesamun indicum L.) flour. Afri. J. Food Sc. 8, 361-367.

20. Mala, K. S., & Kurian, A.K. (2016). Nutritional Composition and Antioxidant Activity of Pumpkin Wastes. Int. J. Pharm. Chem. Biol. Sci. 6, 336-344.

21. Mir, N. A., Gul, K., & Riar, C. S. (2015). Technofunctional and nutritional characterization of gluten-free cakes prepared from water chestnut flours and hydrocolloids. J. Food Process Preserv. 39, 978–984.

22. Mishra, V., Puranik, V., Akhtar, N., & Rai, G. K. (2012). Development and compositional analysis of protein rich soybean-maize flour blended cookies. J. Food Process Tech. 3(9), 1–5.

23. Ndie, E. C., Nnamani, C. V., & Oselebe, H. O. (2010). Some physicochemical characteristics of defatted flours derive from African walnut (Tetracarpidium conoforum): an underutilized legume, Pak. J. Nutr. 9 (9), 909 – 911.

24. Norfezah, M.N., Hardacre, A., & Brennan, C.S. (2011). Comparison of waste pumpkin material and its potential use in extruded snack foods. Food Sc. Tech. Int. 17, 367-373.

25. Oboh, G., Akinyemi, A.J., Ademiluyi, A.O., & Adefegha, S.A. (2010). Inhibitory effects of aqueous extract of two varieties of ginger on some key enzymes linked to Type-2 Diabetes. J. Food Nutr. Res. 49, 14–20.

26. Ogundele, G. F., Ojubanire, B.A., & Bamidele, O. P. (2014): Evaluation of various Characteristics of akara (fried beans cake) made from cowpea (Vigna unguiculata) and soybean (glycine max) blends. J. Exp. Biol. Agric. Sci. 5, 456-459.

27. Ojinnaka M. C., Ihemeje, A., & Ugorji C. O. (2016). Quality evaluation of cookies produced from African breadfruit, wheat and pigeon pea flour blends Am. J. Food Nutr. 3, 101-106.

28. Olagunju, A.I., & Ifesan, B.O.T. (2013). Nutritional Composition and Acceptability of Cookies Made from Wheat Flour and Germinated Sesame (Sesamum indicum) Flour Blends. Br. J. Appl. Sci. Tech. 3, 702-713.

29. Rado˘caj, O., Dimic, E., & Vujasinovic, V. (2012). Development of a hull-less pumpkin (Cucurbita pepo L.) seed oil press-cake spread. J. Food Sci. 77, C1011-C1017.

30. Rezig, L., Chouaibi, M., Msaada, K., & Hamdi, S. (2012): Chemical composition and profile characterization of pumpkin (Cucurbita maxima) seed oil. Ind. Crops Prod. 37, 82-87.

31. Rodr´ıguez-Miranda, J., Hern´andez-Santos, B., Herman-Lara, E., G´omez-Aldapa, C.A., Garcia, H.S., & Mart´ınez-S´anchez, C.E. (2014). Effects of some variables on oil extraction yield from Mexican pumpkin seeds. CyTA –J. Food 12, 9-15.

32. Sengev, I., Gernah, D., & Bunde-Tsegba, M. C. (2015). Physical, Chemical and Sensory Properties Of Cookies Produce From Sweet Potato And Mango Mesocarp Flours, African J. Food, Agric. Nutr. Dev. 15(5), 10428-10442.

33. Sharma, P., & Gujral, H. S. (2014). Cookie making behavior of wheat barley flour blends and effects on antioxidant properties. LWT - Food Sci. Tech. 55: 301–307.

34. Shrestha, A. K., & Noomhorm, A. (2002). Comparison of physicochemical properties of biscuits supplemented with soy and kinema flours. Int. J. Food Sci. Tech. 37, 361–368.

35. Solomakos, N., Govaris, A., Koidis, P., & Botsoglou, N. (2008): The antimicrobial effect of thyme essential oil, nisin, and their combination against Listeria monocytogenes in minced beef during refrigerated storage. Food Micro. 25, 120-127.

36. Sunful, R. E., Sadik, A., & Darko, S. (2010). Nutritional and sensory analysis of soybean and wheat flour composite cake. Pak. J. Nutr. 9, 794 -796.

37. Wheeler, E.L., & Ferrel, R.A. (1971). A method for phytic acid determination in wheat and wheat flour. Cereal Chem. 48, 313-314.

38. Wolford, R., & Banks, D. (2008). “Pumpkins and More.” University of Illinois Extension, USA.

39. Yadav, M., Jain, S., Tomar, R., Prasad, G.B.K.S., & Yadav, H. (2010). Medicinal and biological potential of pumpkin: an updated review. Nutr. Res. Rev. 23, 184–190.

40. Zucco, F., Borsuk, Y., & Arntfield, S. D. (2011). Physical and nutritional evaluation of wheat cookies supplemented with pulse flours of different particle sizes. LWT-Food Sci. Tech. 44, 2070–2076.