First report of European truffle ectomycorrhiza in the semi-arid climate of Saudi Arabia.

Tuber melanosporum Vittad. (Black or Périgord truffle) is a truffle native to the Mediterranean Southern Europe, popular for its unique flavor, and has great economic importance. The present work focused on assessing the possibility of cultivating T. melanosporum associated with Quercus robur L. in the desert climate of Saudi Arabia. The plantation was initiated in November 2018 by planting 271 oak seedlings in the Al-Qassim desert area and checked for survival and ectomycorrhiza development after 1.5 years of plantation maintenance. Amongst the 271 seedlings planted, 243 plants survived two harsh seasons (2019 and 2020), and the randomly selected and tested seedlings were still mycorrhized with T. melanosporum. The mycorrhization level with T. melanosporum was between 5 and 35% of all fine roots, and the share of contaminant ectomycorrhiza was low. In comparison to other areas where T. melanosporum is successfully cultivated, the Al-Qassim desert area has 10-15 °C higher average summer temperatures and a low total annual precipitation, which necessitates regular irrigation of the plantation. This work opens the avenue for an adapted, yet sustainable cultivation of T. melanosporum-inoculated oak tree in a desert climatic condition and introduces new opportunities of the agro-forest business in Saudi Arabia and GCC region.

Co-encapsulation of vitamins B12 and D3 using spray drying: Wall material optimization, product characterization, and release kinetics.

Spray drying is the most commonly used encapsulation technique to stabilize sensitive bioactive compounds and sometimes enhances their performance. Vitamin B12 and vitamin D3 deficiencies are reported worldwide and co-encapsulation can provide a combined solution to this problem. The present work aimed at encapsulation of vitamin B12 and D3 by spray drying using experimental design to optimize wall material combination. Optimized solution obtained from the experimental design (gum acacia : Hi-Cap® 100 : maltodextrin = 38:60:2) provided spherical particles with smooth surface and better stability of both the vitamins. In vitro release mechanism showed a slow release for both the vitamins after encapsulation. The optimized co-encapsulated microcapsules obtained in this work showed an improved bioavailability of 151% for vitamin B12 and 109% for vitamin D3 in comparison with the control. This study delivered a suitable medium to provide water soluble vitamin B12 and fat soluble vitamin D3 in single product.