[Avodah] New Raui LaAchilah Question

[mgluck at gmail.com]

R' MB:
In hopes of creating a new biodegradable option for food wrapping, they came
up with this.

https://bigthink.com/evan-fleischer/paper-plastic-or-crab

    Paper, plastic, or crab?
    July 29, 2018
    by Evan Fleischer

   Researchers at the Georgia Institute of Technology have developed [46]a
   compostable material derived from crab shells and tree fibers that
   might not only be able to replace plastic wrap but could even do a
   better job keeping food fresher for longer than currently available
   non-nature-derived plastic wrap.

My quesrtions were:
1- Could they be used for hot foolds al pi din?
--------------------------------

>From the abstract: "Chitin is an abundant biopolymer whose natural
production is second only to cellulose. Similar to cellulose nanocrystals
(CNCs) or nanofibers (CNFs), chitin nanofibers (ChNFs) can be isolated and
used as sustainable O2 barrier materials for food, electronics, and
pharmaceutical packaging. These bioavailable nanomaterials are readily
dispersed in water enabling spray-coated films to be deposited at high rates
onto uneven or delicate surfaces. In the present study, we demonstrate the
successful layer-by-layer spray coating of cationic ChNF and anionic CNC
suspensions onto poly(lactic acid) (PLA) films."

So we're talking about nanofibers of the crab shell (which, depending on the
crab, may well be edible). Per https://www.ncbi.nlm.nih.gov/pubmed/22539071,
this is how you make chitin nanofibers: "Chitin nanofibers are prepared from
the exoskeletons of crabs and prawns by a simple mechanical treatment after
the removal of proteins and minerals. The obtained nanofibers have fine
nanofiber networks with a uniform width of approximately 10-20 nm and a high
aspect ratio. The method used for chitin-nanofiber isolation is also
successfully applied to the cell walls of mushrooms. They form a complex
with glucans on the fiber surface. A grinder, a Star Burst atomization
system, and a high speed blender are all used in the mechanical treatment to
convert chitin to nanofibers. Mechanical treatment under acidic conditions
is the key to facilitate fibrillation. At pH 3-4, the cationization of amino
groups on the fiber surface assists nano-fibrillation by electrostatic
repulsive force."

I'm just not sure what that second piece means, but I suspect that in that
lies the answer to R' MB's question. Perhaps someone else on-list
understands this and can explain? 

KT,
MYG