Document Type : Original Research Articles.
Authors
1
Department of Science and Technology of Sugar Industry, Faculty of Sugar and Integrated Industries Technology, Assiut University, Assiut 71511, Egypt
2
Assiut University Mycological Centre (AUMC), Assiut University, Assiut
3
Department of Mechanical Power Engineering, Faculty of Engineering, Assiut University, Assiut 71511, Egypt
4
Alexandria Sugar Company (Savola Foods), Burg El Arab 21934, Alexandria, Egypt
5
Department of Food Science and Technology, Faculty of Agriculture, Assiut University, Assiut 71511, Egypt
6
Department of Chemistry, Faculty of Science, Assiut University, Assiut, Egypt
10.21608/esugj.2025.383004.1077
Abstract
This study focuses on the storage of beet thick juice in hot-weather regions like Egypt, where maintaining lower storage temperatures is economically unfeasible and challenging, with the aim of enhancing white sugar yield and mitigating the effects of climate change. Fungal contamination during storage not only compromises the microbial quality of beet thick juice but also poses significant economic risks by reducing product purity and processing efficiency in the sugar industry. This study utilized a pilot plant comprising twelve storage cylinders to store thick beet juice with total soluble solids (ºBrix) of 67, 68, and 69 at 15, 25, and 35 ºC, respectively. Hop ß-acids and KEBOCID 310 biocides were used at 40 ppm, in addition to surface sealing by 25.0% NaOH with air removal. The fungal count (CFUs) was assessed at each treatment. Twelve species of fungi from four genera were isolated and identified, yielding 2334 CFUs in total. Acremonium strictum was the predominant species, accounting for 16.1% of total fungi. Aspergillus niger, A. flavus, A. ustus, and A. terreus ranked the next, constituting 13.1 %, 11.2 %, 11.6 %, and 9.2 % of the total fungi, respectively. Cladosporium cladosporioides (6.9 % of total fungi), was also identified. Penicillium aurantiogriseum, P. chrysogenum, and P. oxalicum comprised 7.9 %, 4.4 %, and 4.9 % of total fungi, respectively. The results indicated that 15 °C was the optimal temperature for preservation, as it yielded the lowest fungal count (375 CFU/mL), whereas 35 °C exhibited the highest overall fungal count (1199 CFU/mL). At each of the three storage temperatures—15, 25, and 35 ºC—the control tanks exhibited higher CFUs compared to the treated tanks. The CFUs in the control tanks exhibited a direct proportional increase with temperature, with 35 ºC yielding the highest CFUs in comparison to 15 and 25 ºC. Tanks containing hop β-acid demonstrated the highest antifungal activity at 15, 25, and 35 °C, as evidenced by the lowest fungal growth recorded at 45, 130, and 174 CFU/mL, respectively.
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