Parameters affecting calcium-alginate bead characteristics: Viscosity of hydrocolloids and water solubility of core material.

In this study, calcium-alginate beads were produced and characterized by ionic gelation technique using three different copolymers (gum arabic (GA), κ-carrageenan (CG), guar gum (GG)), and seven different phenolic compounds (tannic acid, chlorogenic acid, gallic acid, p-coumaric acid, caffeic acid, naringin, and hesperidin). The effect of the viscosity of copolymer and water solubility of the phenolic compound on the size, shape, swelling, encapsulation efficiency (EE), loading capacity (LC), and production yield (PY) of the beads were investigated. In addition, the impact of the core material concentration in the calcium chloride solution on the EE was determined. The bead sizes increased by 6.8, 11.4, and 35.3 %, respectively, with the use of GA, CG, and GG. The EE of the beads ranged from 28.36 to 89.30 % and increased with increasing copolymer viscosity and decreasing water solubility of the phenolic compound. When the core material concentration difference between the alginate and calcium chloride solutions was reduced to zero, the EE of the gallic acid bead increased from 32.95 % to 89.05 %. The results of this study show that copolymer viscosity, the water solubility of core material, and the core material concentration difference between alginate and calcium solutions should be considered in ionic gelation applications.

The role of microencapsulation in maintaining biological activity of royal jelly: comparison with biological activity and bioaccessibility of microencapsulated, fresh and lyophilized forms during storage.

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.

Effects of certain polyphenols and extracts on furans and acrylamide formation in model system, and total furans during storage.

Using a glucose-glycine and asparagine-fructose system as a Maillard reaction model, the effects of seven polyphenols and solid phase extracts of three plants on the formation of furans and acrylamide were investigated. The polyphenols and extracts were used in biscuit formulation and acrylamide formation was observed. They were used for the storage of the glycine-glucose model system at three different temperatures. The addition of some of the extracts and polyphenols significantly decreased furan formation to different extents. All phenolic compounds and plant extracts decreased in the range of 30.8-85% in the model system except for oleuropein, and all of them decreased in the range of 10.3-19.2% in biscuit. Total furan formation was inhibited by caffeic acid, punicalagin, epicatechin, ECE and PPE during storage. This study evaluated and found the inhibitory effect on the formation of furans and acrylamide in Maillard reactions by the use of some plant extracts and polyphenols.

New approaches to determination of HMF.

Several techniques have been used for hydroxymethylfurfural (HMF) detection in foods. Most of these involve the protein hydrolysation step process to determine the presence of organic acid with heat treatment. The affinity and separability of HMF to/from some proteins were exhibited in this study. Also, the dependency of HMF level was determined in the presence of some substances such as reductive and non-reductive sugars, gums and polysaccharides due to high temperature and acidity during the hydrolysation stage. Consequently, the HMF levels of the samples were evaluated separately either by no treatment or by the acid-heat treated method. The HMF amount which was measured by the conventional method was found to be dependent on the sample amount. The binding capacity of HMF to casein was about 10% but did not bind to the gluten in the model system. However it was not released from the caseine by acid hydrolysation in the solvent.