Histological Features of the Olive Seed and Presence of 7S-Type Seed Storage Proteins as Hallmarks of the Olive Fruit Development

Abstract

The production of olive oil is an important economic engine in the Mediterranean area. Nowadays, olive oil is obtained mainly by mechanical processes, by using the whole fruit as the primary raw material. Although the mesocarp is the main source of lipids contributing to olive oil formation, the seed also contributes to the olive oil composition and attributes. The olive seed is also becoming an interesting emerging material itself when obtained after alternative processing of the olive fruit. Such seed is used for the production of differential oil and a unique flour among other bioactive products, with increasing uses and applications in cosmetics, nutrition, and health. However, olive seed histology has been poorly studied to date. A complete description of its anatomy is described for the first time in the present study by using the ‘Picual’ cultivar as a model to study the development of the different tissues of the olive seed from 60 to 210 days after anthesis. A deep analysis of the seed coats, endosperm storage tissue and the embryo during their development has been performed. Moreover, a panel of other olive cultivars has been used to compare the weight contribution of the different tissues to the seed, seed weight variability and the number of seeds per fruit. In addition to the histological features, accumulation of seed storage proteins of the 7S-type (β-conglutins) in the seed tissues has been assessed by both biochemical and immunocytochemical methods. These hallmarks will help to settle the basis for future studies related to the location of different metabolites along the olive seed and mesocarp development, and therefore helping to assess the appropriate ripening stage for different commercial and industrial purposes.

A morphological analysis of fresh and brine-cured olives attacked by <em>Bactrocera oleae</em> using light microscopy and ESEM-EDS

“… 6 The endocarp constitutes 15-22% of the fruit and is composed of a woody coating (sclerenchyma) which encloses the seed and contains small quantities of oil. A complete description of its morphology has been reported for the first time by Zafra et al 7 …”

Nutritional profile and nutraceutical components of olive (Olea europaea L.) seeds

“…vicilins (Zafra et al 2018). Cellular and developmental analyses of the olive seed tissues (Zienkiewicz et al 2014;Zafra et al 2018) suggest a potential to produce oil, proteins and nutraceutical ingredients from olive seeds. Scientific literature about these topics, however, is still limited.…”

Seed Paternity Analysis Using SSR Markers to Assess Successful Pollen Donors in Mixed Olive Orchards

“…For paternity analysis of a large number of samples it is essential to extract high quality DNA. Olive embryos accumulate high contents of polysaccharides, polyphenols, and other secondary metabolites [57,58]. These compounds tend to bind and/or coprecipitate with DNA, interfering with the PCR performance [59].…”