Stereo and Scanning Electron Microscopy of In-Shell Brazil Nut (Bertholletia excelsa HBK): Part Two-Surface Sound Nut Fungi Spoilage Susceptibility

作者：Scussel Vildes M^*; Manfio Daniel; Savi Geovana D; Moecke Elisa H S

来源：Journal of Food Science, 2014, 79(11): H2392-H2403.

DOI：10.1111/1750-3841.12679

• Brazil nut
• edible part
• electron scanning
• fungi
• in-shell
• microscopy
• spoilage

This work reports the in-shell Brazil nut spoilage susceptible morpho-histological characteristics and fungi infection (shell, edible part, and brown skin) through stereo and scanning electron microscopies (SEM). The following characteristics related to shell (a) morphologythat allow fungi and insects' entrance to inner nut, and (b) histologythat allow humidity absorption, improving environment conditions for living organisms development, were identified. (a.1) locule in testaethe nut navel, which is a cavity formed during nut detaching from pods (located at 1.0 to 2.0/4th of the shell B&C nut faces linkage). It allows the nut brown skin (between shell and edible part) first contact to the external environment, through the (a.2) nut channelthe locule prolongation path, which has the water/nutrients cambium function for their transport and distribution to the inner seed (while still on the tree/pod). Both, locule followed by the channel, are the main natural entrance of living organisms (fungi and insects), including moisture to the inner seed structures. In addition, the (a.3) nut shell surfacewhich has a crinkled and uneven surface morphologyallows water absorption, thus adding to the deterioration processes too. The main shell histological characteristic, which also allows water absorption (thus improving environment conditions for fungi proliferation), is the (b.1) cell wall porositythe multilayered wall and porous rich cells that compose the shell faces double tissue layers and the (b.2) soft tissuethe mix of tissues 2 faces corner/linkage. This work also shows in details the SEM nut spoilage susceptible features highly fungi infected with hyphae and reproductive structures distribution.
Practical Application Surface visibly sound in-shell Brazil nuts may end up on consumers' frustration (by getting spoiled the edible inner nut part) after de-shelling. That can also influence country's economy by whole batches' quality reducing and/or trade rejection. By knowing the whole nuts fungi susceptibility sites and characteristics, more precise/effective fungi control methods can be applied and developed.

• 出版日期2014-11