Proteomic changes associated with the development of açaí ( Euterpe oleracea Mart.) seeds

Mattos

Nascimento

et al. 2022

J. Agric. Food Chem.

Self Cite

We investigated changes in the phenolic profile and antioxidant properties in the extracts of developing seeds of acai (Euterpe oleracea). Four developmental stages were evaluated, with earlier stages displaying higher antioxidant activity and polyphenols content, while mass spectrometry analysis identified procyanidins (PCs) as the major components of the extracts in all stages. B-type PCs varied from dimers to decamers, with A-type linkages in a smaller number. Extracted PCs decreased in average length from 20.5 to 10.1 along seed development. PC composition indicated that (−)-epicatechin corresponded to over 95% of extension units in all stages, while (+)-catechin presence as the starter unit increased from 42 to 78.8% during seed development. This variation was correlated to the abundance of key enzymes for PC biosynthesis during seed development. This study is the first to report PC content and composition variations during acai ́seed development, which can contribute to studies on the plant's physiology and biotechnological applications.

Section: Resultsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Section: Identification Of Procyanidins Inmentioning

confidence: 99%

See 1 more Smart Citation

Phenolic Profile and Antioxidant Properties in Extracts of Developing Açaí (Euterpe oleracea Mart.) Seeds

Mattos

Nascimento

et al. 2022

J. Agric. Food Chem.

Self Cite

“…However, there is a very small amount of information about the localization of primary compounds in açaí seeds. A previous study has quantitatively analyzed the proteome dynamics and morphological aspects of the açaí pericarp and seed during the developmental stages 17,18 . Also, a recent histochemical study provided the presence of phenolic compounds and carbohydrates in the açaí seed coat and endosperm, respectivelly 19 .…”

Section: Introductionmentioning

confidence: 99%

Acquiring thin histological sections of açaí (Euterpe oleracea Mart.) seeds for molecular mapping by mass spectrometry imaging

Brum

Mohana‐Borges

et al. 2022

Preprint

RATIONALE: Matrix-assisted laser desorption/ionization imaging mass spectrometry (MALDI-IMS) of tissues became popular in the last decade. Consequently, adapting sample preparation methods for different materials turned to be a pivotal step for a successful analysis, due to the requirement of samples slices of 12-20 µm thickness. However, preparing thin sections compatible with MALDI-IMS for unusual samples is challenging, as existing histological protocols may not be suitable, thus requiring new methods. Açaí (Euterpe oleracea Mart.) seed is an example of a challenging material due to its toughness and resistance to crack. Therefore, our goal was to develop a methodology to obtain thin (<20 µm) and entire longitudinal sections of açaí seeds for MALDI-IMS analysis. METHODS: Different strategies were evaluated for obtaining thin cuts of seeds, being the combination of the following steps the most suitable option: (i) softening of seeds by water immersion for 24 h; (ii) longitudinal cut of seeds to obtain half-seeds using a razor blade and a hammer; (iii) half-seeds imbibition in gelatin; (iv) sectioning using a cryostat at -20 °C to obtain samples with <20 µm thickness; and (v) collection of samples in an indium tin oxide coated glass slide covered by a double-face copper tape to avoid sample wrapping and ensure adhesion after unfreezing. (iv) storage of samples in a -80 °C freezer, if necessary. RESULTS: As a result, this adapted sample preparation method enabled the analysis of açaí seeds by MALDI-IMS providing spatial distribution of carbohydrates in the endosperm. CONCLUSIONS: The adaptations developed for sample preparation will help investigate the metabolic and physiological properties of açaí seeds in future studies.

The acquisition of thin sections of açaí (Euterpe oleracea Mart.) seed with elevated potassium content for molecular mapping by mass spectrometry imaging

Brum

Rapid Comm Mass Spectrometry

Mohana‐Borges

et al. 2023

RationaleMatrix‐assisted laser desorption/ionization imaging mass spectrometry (MALDI‐IMS) of tissues became popular in the last decade. Consequently, adapting sample preparation methods for different materials turned out to be a pivotal step for successful analysis due to the requirement of sample slices of 12–20 μm thickness. However, acquiring thin sections compatible with MALDI‐IMS for unusual samples is challenging, as existing histological protocols may not be suitable, thus requiring new methods. Açaí (Euterpe oleracea Mart.) seed is an example of a challenging material due to its toughness and resistance to crack, therefore our goal was to develop a methodology to obtain thin (12–20 μm) and entire sections of açaí seeds for MALDI‐IMS analysis.MethodsDifferent strategies were evaluated for obtaining thin sections of seeds, and the combination of the following steps was found to be the most suitable option: (i) softening of seeds by water immersion for 24 h; (ii) transversal cut of seeds to obtain half‐seeds using a razor blade and a hammer; (iii) half‐seeds imbibition in gelatin; (iv) samples sectioning using a cryostat at −20°C to obtain samples with 12–20 μm thickness; (v) collection of samples in an indium tin oxide‐coated glass slide covered by double‐sided copper tape to avoid sample wrapping and ensure adhesion after unfreezing; and (vi) storage of samples in a −80°C freezer, if necessary.ResultsThis adapted sample preparation method enabled the analysis of açaí seeds by MALDI‐IMS, providing spatial distribution of carbohydrates in the endosperm.ConclusionsThe adaptations developed for sample preparation will help investigate the metabolic and physiological properties of açaí seeds in future studies.