Investigation of the use of bee bread in probiotic yogurt production and its effect on physicochemical, microbiological and sensory properties

Bee bread is a food source that is formed by the fermentation of pollen collected by worker bees to feed their larvae. Bee bread has a higher digestibility rate in humans than pollen. The effect of bee bread added to yogurt at ratios of 0.5%, 1%, and 2% on the physicochemical, microbiological and sensory properties of yogurt samples was investigated in this study. Organic acid content in bee bread was analyzed using high liquid pressure chromatography-HPLC; aroma profile was analyzed using gas chromatography-mass spectrometry-GC/MS; mineral content was analyzed using inductively coupled plasma-optic emission spectroscopy-ICP-OES; and antioxidant activity of bee bread was determined using the 1,1-diphenyl-2-picrylhydrazyl-DPPH method. The experimental groups were provided with the probiotic Lactobacillus acidophilus LA-5 bacteria. The mineral substances detected in the content analysis of bee bread were B, Ca, Fe, K, Mg, Na, P, and Zn. However, the presence of Cr, Mn, and Mo could not be determined. The analysis of sugar composition revealed the presence of fructose (149.4 mg/g), glucose (92 mg/g), and sucrose (21.1 mg/g). The organic acid content was assessed and the following values were obtained: oxalic acid (1.26 mg/g), malic acid (7.79 mg/g), ascorbic acid (0.91 mg/g), and citric acid (2.73 mg/g). The assessment of phenolic substance content led to the determination of p-coumaric acid (15.3 µg/g) and kaempferol (5562.4 µg/g) contents. The study determined the tocopherol content, specifically alpha (7.09 µg/g), beta (0.4 µg/g), gamma (0.77 µg/g), and delta (0.31 µg/g). The quantification of tocopherol and total tocopherol content yielded a value of 8.57 µg/g in the form of total tocopherol. A total of 55 distinct components were identified during the analysis of the volatile and aroma profiles. In this study, it was found that the IC50 value of bee bread was 1.414 mg/mL. Bee bread had no effect on physicochemical parameters such as pH, acidity, dry matter, ash, fat, water holding capacity (p>0.05), but had an effect on protein and syneresis (p<0.05). The addition of bee bread had a positive effect on Streptococcus thermophilus and L. bulgaricus and that L. acidophilus LA-5 activity was preserved at around 107 kob/g during storage (p<0.05). The addition of bee bread affected the color parameters L*, a*, b* values (p<0.05). The group that contained 0.5% bee bread was determined to be preferred based on the analysis of sensory values. The study findings indicate that bee bread maintains an important value as a bee product, owing to the components that compose its composition. The study has demonstrated that the addition of bee bread during yogurt production can effectively maintain probiotic activity. Findings from studies indicate that yoghurts containing bee bread are perceived by consumers as a health-promoting product. There is a need to conduct creative studies on the consumption of bee bread.