Oleosomes in almonds and hazelnuts: structural investigations by NMR

Oleosomes are lipid-containing organelles that store oils and fats in the
tissues of seeds such as almonds and hazelnuts. A comprehensive and
detailed understanding and measurement of their size and distribution is
necessary to capture the physical properties of almond- or hazelnut-
containing foods and to improve their quality. During processing, almonds
and hazelnuts are blanched or roasted and crushed, leading to structural
changes in their tissues. In addition, nut butter contains quasi-free oil.
Pulsed-field gradient nuclear magnetic resonance (PFG-NMR) is applied
to determine the size distribution of the oleosomes and to monitor
the structural changes along the process chain. A model established for
droplet size determination in emulsions was applied and extended to the
present case.