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In this study, effect of temperature (4, 10, 25, and 35°C) on microstructural and rheological properties of royal jelly (RJ) was investigated. Our results indicated that pH and proximate composition of RJ was insignificantly affected by temperature, but °Brix values increased. Microstructural images showed that RJ particles were homogeneous at 10 and 25°C, but swelled at 35°C. RJ samples showed shear thinning behavior with yield stress. The increasing temperature caused the increase of yield stress due to swelling of particles. All samples were characterized as weak gel‐like behavior because G′ > G″ at up to 100 rad/s. Three interval thixotropic test (3ITT) showed that RJ samples could partially recover after high shear deformation, but increasing temperature decreased recovery percentage of samples. This study revealed that the temperature of RJ should never exceed to 10°C to obtain better recovery during the processing.Practical applicationsApicultural products such as royal jelly (RJ) have become very important nutritional products in recent times due to bioactive properties and are increasingly attracted by consumers. Bioactive properties of RJ can highly be deteriorated by process temperature and storage conditions. RJ has creamy and milk‐like structure and contains high amounts of proteins and carbohydrates. Therefore, the rheological characterization of RJ can provide significant information about structure, freshness, end product quality for consumers, as well as process equipment design and energy consumption for manufacturers. The freshness of RJ is determined with the analysis of 10‐HDA, furosine, superoxide dismutase and 57 kDa proteins. This study revealed that the rheological characterization of RJ at different temperatures may be helpful to estimate freshness and process conditions easier than analytical methods.

BACKGROUND Royal jelly (RJ) is a unique beehive product and has been recommended for human health since ancient times because of its antioxidant, antimicrobial, antiproliferative, neuroprotective, anti‐lipidemic and anti‐aging features. However, the biggest obstacle in the use of RJ is the need for cold storage and the instability of bioactive components over time. In the present study, 10‐hydroxy‐2‐decenoic acid (10‐HDA) content, as well as antioxidant [using 1,1‐diphenyl‐2‐picrylhydrazy and 2,2′‐azino‐bis(3‐ethylbenzthiazoline‐6‐sulfonic acid) methods] and antimicrobial activity (five Gram‐positive, five Gram‐negative and three yeasts), were comparatively evaluated for three RJ forms, two of which can be stored at 24 ± 1 °C during storage. RESULTS Microencapsulated royal jelly (MRJ) stored at room temperature succeeded in preserving its 10‐HDA content, a major bioactive compound, during the 6 months, with respect to lyophilized royal jelly (LRJ) and fresh RJ stored at 4 °C. The initial 10‐HDA contents of RJ, LRJ and MRJ were determined as 1.90%, 5.26% and 2.75%, respectively. Moreover, the total phenolic content, antioxidant capacity and antimicrobial activity mostly remained constant throughout the storage period (P ≥ 0.05). Gram‐positive strains were generally more sensitive than Gram‐negative strains. In the present study, the in vitro simulated digestion analysis showed that MRJ can tolerate the digestion process. CONCLUSION Overall, the encapsulation process was considered as one preservative technique for RJ. The microencapsulation of RJ as shown in the results of the present study are encouraging in terms of enabling the local beekeeping sector to achieve ease of production and increased product diversity. MRJ shows promise as a commercial product with a high export value for producers. © 2022 Society of Chemical Industry.

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