EC Nutrition

Objective: This study was conducted to evaluate the chemical composition of Yoghurt manufactured by different whey levels during the different storage periods.

Methods: Yogurt samples were manufactured (day one) from five different levels of whey (A, B, C, D, and E), transported to the laboratory in an ice box, and stored at 7°C for 14 days. Samples were analyzed for total solids, moisture, ash, curd protein, fat, pH and acidity at 1, 7 and 14 days.

Results: The results showed that fat, protein, total solids, ash, and pH were high in A and low in E, except for acidity which was increased in E low in C. During storage fat, protein, ash contents, and pH decreased to a minimum at day 14, except for total solids and acidity increased to a maximum at day 14. Towards the end of storage, the fat content slightly decreased in E and increased in A. The protein content reduced somewhat towards the end in E and increased in A. The total solids and ash contents somewhat reduced in all treatments at the end of storage, while acidity increased towards the end of storage in all treatments.

Keywords: Yoghurt; Whey Levels; Chemical Composition; Storage Period

1. Adolfsson O., et al. “Yogurt and Gut Function". The American Journal of Clinical Nutrition 80 (2004): 245-256.
2. Cultures for Health “What is Yoghurt” (2015).
3. Chandan RC., et al. “Manufacturing Yogurts and fermented milk”. First Edition, Blackwell Publishing, Blackwell Publishing Professional 2121 State Avenue, Ames, Iowa 50014, USA (2006).
4. Han X Lee F L., et al. “Chemical Composition of Water Buffalo Milk and its Low-Fat Symbiotic Yogurt Development”. Journal of Functional Foods in Health and Disease4 (2012): 86-106.
5. Paszczyk B., et al. “The effect of storage on the yogurt fatty acid profile”. Mljekarstvo1 (2020): 59-70.
6. Gajendra Bohora. “Preparing a whey-based pineapple beverage and its storage quality evaluation”. B. Tech Thesis, in Food Technology Tribhuvan University Nepal (2018).
7. Baldasso C., et al. “Concentration and purification of whey proteins by ultrafiltration”. Journal of Desalination 3 (2011): 381-386.
8. Lacta SA. “Biotechnological valorisation of whey”. Journal detail: Innovative Romanian Food Biotechnology 3 (2012): 1-8.
9. AOAC "Curd Protein in yogurt”. (12^th) Association of Official Analytical Chemists 981.10. (2003).
10. Authority of India Ministry of Health and Family Welfare Government. “Manual of Methods of Analysis Food (Milk and milk product)”. Food safety and standards of India P128 (2015).
11. AOAC "Official Methods of Analysis". (12^th edition) Association of Official Analytical Chemists Washington D.C. (2005).
12. AOAC International. “Official Methods of Analysis” 20^th edition AOAC International, Gaithersburg, MD (2016).
13. Schorsch C., et al. “Gelation of casein-whey mixtures: Effects of heating whey proteins alone or in the presence of casein micelles”. Journal of Dairy Research 68 (2001): 471-481.
14. Vukic VR., et al. “The effect of kombucha starter culture on the gelation process, microstructure, and rheological properties during milk fermentation”. The Journal of Texture Studies 45 (2014): 261-273.
15. Bierzuńska P., et al. “Storage stability of texture and sensory properties of yogurt with the addition of polymerized whey proteins”. Foods11 (2019): 548.
16. Shah NP., et al. “Survival of Lactobacillus acidophilus and Bifidobacterium bifidum in commercial Yoghurt during refrigerated storage”. The International Dairy Journal 5 (1995): 515-521.
17. Wang W., et al. “Consistency, microstructure, and probiotic survivability of goats' milk yogurt using polymerized whey protein as a co-thickening agent”. The International Dairy Journal 24 (2012): 113-119.
18. Olson DW and Aryana KJ. “An excessively high Lactobacillus acidophilus inoculation level in yogurt lowers product quality during storage”. LWT - Food Science and Technology5 (2008): 911-918.
19. Nergiz C and Seçkin AK. “The losses of nutrients during the production of strained (Torba) yoghurt”. Food Chemistry 61-1-2 (1998): 13-16.