Document Type : Full Research Paper

Authors

1 Department of Food Science and Technology, ACECR Kashmar Higher Education Institute, Kashmar, Iran

2 Department of Food Quality and Safety, Food Science and Technology Research Institute, ACECR Khorasan Razavi Branch, Mashhad, Iran

Abstract

Introduction: Yogurt is one of the most popular dairy products, which has numerous health effects on human body. Dietary fiber consumption is highly recommended. Fibers are highly hydrophilic and absorb water into the digestive track, increase the volume of food and thereby facilitating excretion. These are some health benefits of these compounds. Consumption of fiber-containing yogurt can be helpful for people who suffer from cardiovascular diseases, hypertension, diabetes and obesity. Zucchini, as a vegetable, is a source of fibers and due to its health-promoting effects, can be used in dairy products. The aim of this study is to evaluate the effects of different levels of dried zucchini on stirred yogurt during storage.
 
Materials and Methods: The raw materials for the production of the functional yogurt were zucchini, milk, skim milk powder, whey powder, hydrocolloids stabilizer compound and starter culture. Fresh zucchini was hot-air dried at 70 °C for 7 hours. Two forms of the dried zucchini (powder and granule) were added to fresh yogurt at levels of 0.7, 1.4, and 2%. The samples were then tested on days 1, 5, 10 and 15 for acidity (titration method), pH, texture stiffness (back extrusion), syneresis, color (using image processing) and sensory properties, including color, taste, aroma, consistency, mouthfeel and overall acceptance. The experiments were triplicated and analysis of variance was performed using Minitab software at 95% confidence interval. For the significant variables, the means were compared using LSD method. Graphs were drawn using MS-Excel.
 
Results and Discussion: The effects of zucchini form and level of addition, storage time and interaction of these variables were significant (P<0.05) on the titratable acidity, pH and firmness. Over time, pH decreased and acidity increased, which was related to the starter activity and acid production. Due to the use of stabilizer and whey protein, all samples showed no syneresis. The firmness of the samples containing zucchini powder was higher than that of the granule- (P<0.05). This might be related to the homogeneous structure of zucchini fiber, which increased water absorption regarding its lower particle size. Firmness increased from day one to day five, due to the high water absorption of hydrocolloids that bind to free water present in the yogurt structure. The presence of milk proteins and whey protein concentrate in the yogurt formula enhanced crosslinking in the particle gel network, which resulted in a stronger gel structure. During longer storage, firmness decreased from day 5 to day 10, probably was due to the increased pH, which affects the proteins and polysaccharides interaction. The effects of the form and level of zucchini and the interaction between these variables were significant (p <0.05) on the changes in L*, a*, and b*. The L* and a* values which were higher in the samples containing zucchini granules than in the zucchini powder, most probably due to the smaller particle sizes of the powder compared with the granules, causing the number of the powder particles per unit volume to be larger and the powder-containing samples to become darker. In terms of the level of addition, L* increased as the zucchini level rose to 1.4% and then declined to 2%. The sensory properties of all samples were significantly affected by the storage time (P<0.05). With increase in the storage time, all the sensory scores increased. The highest overall acceptance score belonged to the yogurt sample containing 1.4% granule on the 10th day of storage. Overall, zucchini is a good candidate for yogurt fortification. This incorporation results in a greenish yogurt with more health functionalities. The highest overall acceptance score was obtained for the yogurt containing 1.4% zucchini granule on the 10th day of storage (best consumption date) and the results showed acceptable firmness for this sample.

Keywords

Ehtiati, A,. Mohebi, M,. Shahidi, F. 2008. Application of image processing in soy flour fortified bread colorimetry. The 18th National Congress of Food Science and Technology, October 24 and 25, Mashhad.
Hayatinegad, J,. Mohamadi sani, A,. Hojjat al-Islami. 2013. Optimization of formulation of flavored cast yogurt enriched with Spinacia oleracea extract and measurement of its physicochemical, sensory and microbial properties during storage. Second National Conference on Food Science and Technology. May 9-10. Islamic Azad University of Quchan Branch.
Tohidzadeh, M,. Khosrowshahi asl, A,. Zomorodi, SH & Elham Rad, A. 2013. Effect of carrot fiber on Lactobacillus casei survival and apricot yogurt quality using response surface methodology. Journal of Innovation in Food Science and Technology. 6 (1): 122-114.
Foroughani, S,. Peygambar dost, s,. Elad Ghafari, a. 2017. Investigation of physical and chemical sensory properties of processed yogurt containing oat milk. Iranian Journal of Biosystems Engineering. 48 (3): 288-279.
Mohammadi Elasti, F, Fadaei Noghani and Khosravi Darani, K. 2016. Effect of different concentrations of Spirulina platensis on some chemical and sensory properties of probiotic spinach yogurt. Journal of Food Industry Research. 26 (2): 142-128.
Institute of Standards and Technology of Iran, 2006, Fer and its Products-pH; Idea and Test Method of Iranian Standard, No. 2852.
Yard melat, M. 2017. Effect of using some native gum on the physicochemical, tissue and sensory properties of yogurt. MSc in Food Science and Technology, Faculty of Animal Sciences and Food Technology, Ramin University of Agriculture and Natural Resources, Khuzestan, Iran.
AMATAYAKUL, T., HALMOS, A., SHERKAT, F. & SHAH, N. 2006. Physical characteristics of yoghurts made using exopolysaccharide-producing starter cultures and varying casein to whey protein ratios. International Dairy Journal, 16, 40-51.
AYAR, A. & GURLIN, E. 2014. Production and sensory, textural, physico-chemical properties of flavored spreadable yogurt. Life Science Journal, 11, 58-65.
AZARI-ANPAR, M., TEHRANI, N. S., AGHAJANI, N. & KHOMEIRI, M. 2017. Optimization of the new formulation of ice cream with native Iranian seed gums (Lepidium perfoliatum and Lepidium sativum(using response surface methodology (RSM.) Journal of food science and technology, 54, 196-208.
AZARI‐ANPAR, M., PAYEINMAHALI, H., DARAEI GARMAKHANY, A. & SADEGHI MAHOUNAK, A. 2017. Physicochemical, microbial, antioxidant, and sensory properties of probiotic stirred yoghurt enriched with Aloe vera foliar gel. Journal of food processing and preservation, 41, e13209.
AZIZNIA, S., KHOSROWSHAHI, A., MADADLOU, A. & RAHIMI, J. 2008. Whey protein concentrate and gum tragacanth as fat replacers in nonfat yogurt: chemical, physical, and microstructural properties. Journal of Dairy Science, 91, 2545-2552.
BAKIRCI, I. & KAVAZ, A. 2008. An investigation of some properties of banana yogurts made with commercial ABT‐2 starter culture during storage. International Journal of Dairy Technology, 61, 270-276.
BEHNIA, A., KARAZHIYAN, H., NIAZMAND, R. & MOHAMMADI, N. A. 2014. Effect of Cress seed gum on rheological and textural properties of lowfat yoghurt.
BONCZAR, G., WSZOŁEK, M. & SIUTA, A. 2002. The effects of certain factors on the properties of yoghurt made from ewe’s milk. Food Chemistry, 79, 85-91.
CORBO, M. R., ALBENZIO, M., DE ANGELIS, M., SEVI, A. & GOBBETTI, M. 2001. Microbiological and biochemical properties of Canestrato Pugliese hard cheese supplemented with bifidobacteria. Journal of Dairy Science, 84, 551-561.
DAVE, R. I. & SHAH, N. P. 1998. Ingredient Supplementation Effects on Viability of Probiotic Bacteria in Yogurt. Journal of Dairy Science, 81, 2804-2816.
DHIMAN, K., GUPTA, A., SHARMA, D., GILL, N. & GOYAL, A. 2012. A review on the medicinally important plants of the family Cucurbitaceae. Asian J Clin Nutr, 4, 16-26.
FARAHAT, A. M. & EL-BATAWY, O. 2013. Proteolytic activity and some properties of stirred fruit yoghurt made using some fruits containing proteolytic enzymes. World Journal of Dairy and Food Sciences, 8, 38-44.
GARCÍA‐PÉREZ, F., LARIO, Y., FERNÁNDEZ‐LÓPEZ, J., SAYAS, E., PÉREZ‐ALVAREZ, J. & SENDRA, E. 2005. Effect of orange fiber addition on yogurt color during fermentation and cold storage. Color Research & Application: Endorsed by Inter‐Society Color Council, The Colour Group (Great Britain(, Canadian Society for Color, Color Science Association of Japan, Dutch Society for the Study of Color, The Swedish Colour Centre Foundation, Colour Society of Australia, Centre Français de la Couleur, 30, 457-463.
GODARZI, O., MAZAHERI, T. M. & PORAZERANG, H. 2015. OPTIMIZATION OF FORMULATION FERMENTED DRINK YOGHURT WITH FRUIT JUICE USING RESPONSE SURFACE METHODOLOGY.
GRUBBEN, G. 2004. Amaranthus cruenthus in Grubben. GJH & Denton, OA (Editors.) Plants resources of tropical Africa 2. Vegetables PROTA foundation, Wageningen, Netherlands. Backhuys Publishers, Leiden, Netherlands/CTA, wageningen, Netherlands.
GUINÉ, R. P., PINHO, S. & BARROCA, M. J. 2011. Study of the convective drying of pumpkin (Cucurbita maxima.) Food and bioproducts processing, 89, 422-428.
HASANI, S., KHODADADI, I. & HESHMATI, A. 2016. Viability of Lactobacillus acidophilus in rice bran‐enriched stirred yoghurt and the physicochemical and sensory characteristics of product during refrigerated storage. International Journal of Food Science & Technology, 51, 2485-2492.
HASANI, S., SARI, A. A., HESHMATI, A. & KARAMI, M. 2017. Physicochemical and sensory attributes assessment of functional low‐fat yogurt produced by incorporation of barley bran and Lactobacillus acidophilus. Food science & nutrition, 5, 875-880.
HAYATY NEJAD, J., MOHAMADI SANI, A. & HOJJATOLESLAMY, M. 2014. Sensory acceptability and quality of flavored yogurt enriched with Spinacia oleracea extract. Nutrition & Food Science, 44, 182-192.
KAILASAPATHY, K., HARMSTORF, I. & PHILLIPS, M. 2008. Survival of Lactobacillus acidophilus and Bifidobacterium animalis ssp. lactis in stirred fruit yogurts. LWT-Food Science and Technology, 41, 1317-1322.
KARAMI, M. & ASADI, J. 2017. RHEOLOGICAL, PHYSICO-CHEMICAL AND SENSORIAL ATTRIBUTES OF STIRRED YOGHURT WITH IRRADIATED AND AUTOCLAVED THYME.
KATSIARI, M. C., VOUTSINAS, L. P. & KONDYLI, E. 2002. Manufacture of yoghurt from stored frozen sheep’s milk. Food chemistry, 77, 413-420.
KOK, C. R. & HUTKINS, R. 2018. Yogurt and other fermented foods as sources of health-promoting bacteria. Nutrition reviews, 76, 4-15.
KUMAR, P. & MISHRA, H. 2004. Mango soy fortified set yoghurt: effect of stabilizer addition on physicochemical, sensory and textural properties. Food Chemistry, 87, 501-507.
LADJEVARDI, Z, GHARIBZAHEDI, S. & MOUSAVI, M. 2015. Development of a stable low-fat yogurt gel using functionality of psyllium (Plantago ovata Forsk(husk gum. Carbohydrate Polymers, 125, 272-280.
MOUSAVI, M., HESHMATI, A., DARAEI GARMAKHANY, A., VAHIDINIA, A. & TAHERI, M. 2019. Texture and sensory characterization of functional yogurt supplemented with flaxseed during cold storage. Food science & nutrition, 7, 907-917.
NEVES, F. I., VIEIRA, M. C. & SILVA, C. L. 2012. Inactivation kinetics of peroxidase in zucchini (Cucurbita pepo L.)by heat and UV-C radiation. Innovative Food Science & Emerging Technologies, 13, 158-162.
ÖZCAN, T. & YıLDıZ, E. 2016. Determination of Textural and Sensory Properties of Yogurt Produced with The Vegetable Puree. Turkish Journal of Agriculture-Food Science and Technology, 4, 579-587.
PASEEPHOL, T., SMALL, D. M. & SHERKAT, F. 2008. Rheology and texture of set yogurt as affected by inulin addition. Journal of Texture Studies, 39, 617-634.
PUVANENTHIRAN, A., WILLIAMS, R. & AUGUSTIN, M. 2002. Structure and visco-elastic properties of set yoghurt with altered casein to whey protein ratios. International Dairy Journal, 12, 383-391.
RADI, M., NIAKOUSARI, M. & AMIRI, S. 2009. Physicochemical, textural and sensory properties of low-fat yogurt produced by using modified wheat starch as a fat replacer. Journal of Applied Sciences, 9, 2194-2197.
RAMIREZ-SANTIAGO, C., RAMOS-SOLIS, L., LOBATO-CALLEROS, C., PEÑA-VALDIVIA, C., VERNON-CARTER, E. & ALVAREZ-RAMÍREZ, J. 2010. Enrichment of stirred yogurt with soluble dietary fiber from Pachyrhizus erosus L. Urban: Effect on syneresis, microstructure and rheological properties. Journal of Food Engineering, 101, 229-235.
RAMÍREZ-SUCRE, M. O. & VÉLEZ-RUIZ, J. F. 2013. Physicochemical, rheological and stability characterization of a caramel flavored yogurt. LWT-Food Science and Technology, 51, 233-241.
RASDHARI, M., PAREKH, T., DAVE, N., PATEL, V. & SUBHASH, R. 2008. Evaluation of various physico-chemical properties of Hibiscus sabdariffa and L. casei incorporated probiotic yoghurt. Pak J Biol Sci, 11, 2101-8.
REMEUF, F., MOHAMMED, S., SODINI, I. & TISSIER, J. 2003. Preliminary observations on the effects of milk fortification and heating on microstructure and physical properties of stirred yogurt. International Dairy Journal, 13, 773-782.
RÓŻYŁO, R, GAWLIK-DZIKI, U, DZIKI, D, JAKUBCZYK, A, KARAŚ, M. & RÓŻYŁO, K. 2014. Wheat bread with pumpkin (Cucurbita maxima L.)pulp as a functional food product. Food technology and biotechnology, 52, 430-438.
SADEGHI, A. 2016. In vitro Assessment of Some Probiotic Properties of Lactobacillus fermentum Isolated from Pickled Garlic. Journal of food quality and hazards control, 3, 67-72.
SAFARI, N., FAZEL, M. & JAHADI, M. 2017. INVESTIGATION THE EFFECT OF ALLIUM CANADANSE PLANT POWDER ON PHYSICOCHEMICAL PROPERTIES OF STIRRED YOGHURT.
SCHMIDT, K. & SMITH, D. E. 1992. Rheological properties of gum and milk protein interactions. Journal of Dairy Science, 75, 36-42.
SENDRA, E., KURI, V., FERNANDEZ-LOPEZ, J., SAYAS-BARBERA, E., NAVARRO, C. & PEREZ-ALVAREZ, J. 2010. Viscoelastic properties of orange fiber enriched yogurt as a function of fiber dose, size and thermal treatment. LWT-Food Science and Technology, 43, 708-714.
SHAKERIAN, A., SOHRABI, M.-J. & GHASEMI PIRBALOUTI, A. 2012. Effect of Bakhtiari celery (Kelussia odoratissma Mozaff(on sensory properties and shelf life of set yogurt. Journal of Herbal Drugs (An International Journal on Medicinal Herbs(, 3, 41-48.
SHORI, A. B. & BABA, A. S. 2012. Viability of lactic acid bacteria and sensory evaluation in Cinnamomum verum and Allium sativum-bio-yogurts made from camel and cow milk. Journal of the Association of Arab Universities for Basic and Applied Sciences, 11, 50-55.
SODINI, I, REMEUF, F, HADDAD, S. & CORRIEU, G. 2004. The relative effect of milk base, starter, and process on yogurt texture: a review. Critical reviews in food science and nutrition, 44, 113-137.
STAFFOLO, M. D., BERTOLA, N. & MARTINO, M. 2004. Influence of dietary fiber addition on sensory and rheological properties of yogurt. International Dairy Journal, 14, 263-268.
SUDHA, M, VETRIMANI, R. & LEELAVATHI, K. 2007. Influence of fibre from different cereals on the rheological characteristics of wheat flour dough and on biscuit quality. Food chemistry, 100, 1365-1370.
TARAKCI, Z. 2010. Influence of kiwi marmalade on the rheology characteristics, color values and sensorial acceptability of fruit yogurt. Kafkas Univ Vet Fak Derg, 16, 173-178.
TARAKÇI, Z. & KUCUKONER, E. 2003. Physical, chemical, microbiological and sensory characteristics of some fruit-flavored yoghurt. YYÜ Vet Fak Derg, 14, 10-14.
WASHINGTON, N, HARRIS, M, MUSSELLWHITE, A. & SPILLER, R. C. 1998. Moderation of lactulose-induced diarrhea by psyllium: effects on motility and fermentation. The American journal of clinical nutrition, 67, 317-321.
YOUSEF, M., NATEGHI, L. & AZADI, E. 2013. Effect of different concentration of fruit additives on some physicochemical properties of yoghurt during storage. Annals of Biological Research, 4, 244-249.
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