Work

Nutritional, bioactive, and quality attributes of almond-based fermented beverage (ayran-type): effects of pasteurisation, fermentation pH, and storage

Year: 2026

Type: article

Abstract: The effects of pasteurisation temperature (PT, 70 and 85 °C) and fermentation end-point pH (4.4 and 4.6) on the physicochemical, microbiological, bioactive, and sensory properties of an almond-based fermented ayran-type beverage were evaluated during 21 days of refrigerated storage. The PT was the main factor affecting product quality. Beverages pasteurised at 85 °C exhibited significantly higher dry matter, protein, and fat contents; higher viscosity; and markedly lower serum separation, than those pasteurised at 70 °C (p < .05), whereas a temperature of 70 °C better preserved the total phenolic content, cupric reducing antioxidant capacity (CUPRAC), and ferric reducing antioxidant power (FRAP) values. Fermentation end-point pH had generally limited effects, with significant differences observed only for viscosity, serum separation (%) and FRAP values. During refrigerated storage, starter culture viability gradually declined, although Streptococcus thermophilus remained above 7 log colony-forming units (CFU) g−1. Concurrently, yeast populations increased and sensory quality progressively decreased. Overall, pasteurisation at 85 °C, particularly in combination with fermentation to a pH of 4.6, provided the most favourable balance between physical stability and sensory quality.

Source: International Journal of Food Science & Technology

DOI: 10.1093/ijfood/vvag160

Authors: İdil Dibek, Ercan Sarica

Institution: Bolu Abant İzzet Baysal University

Language: English

Topic: Probiotics and Fermented Foods

Subfield: Food Science

Field: Agricultural and Biological Sciences

Domain: Life Sciences

SDG: Zero hunger

Open Access status: gold

Estimated APC paid: $2,638