consolidation of the gel
14 ChemMatters | FEBRUARY/MARCH 2018
Many people are skeptical
about edible food packaging ever being widely adopted. Sure, the
ice cream cones and bread bowls have found their niche, and we eat
the skins on apples and grapes, but come on people! The plastic isn’t
the only reason you don’t eat a water bottle. Think of the filth! The jour-
ney from hand to hand. Did everyone (including you) wash their hands
properly? Was it stored near or did it ever sit on anything that wasn’t
100% hygienic? Also, if these products are ever sold at grocery
stores it will mean selling them with external packaging (think
M&Ms™), completely negating the “package-free”
mission. Why not use biodegradable or reusable packaging
and skip the edible packaging?
store, but this problem can be avoided by
placing the skin-wrapped food in biodegradable cellophane. In the future, Edwards hopes
to expand the application of WikiCell beyond
frozen yogurt to other foods and beverages.
Eating and drinking
Disposable cups, bowls, and plates are regularly used at birthday parties, cookouts, and
other events. While these items are convenient
and help the hosts avoid dealing with piles of
dishes, they only add more nonbiodegradable
waste to our landfills.
Six years ago, recent college graduates
Chelsea Briganti and Leigh Ann Tucker sought
to change the way we consume our beverages
at parties and other gatherings. “Every year,
Americans throw away 25 billion plastic cups
that end up in landfills, never to decompose,”
Briganti and Tucker said. “We wanted to find
a solution.” Thus, LOLIWARE was born.
Briganti and Tucker successfully created one
of the first edible and
compostable cups to
replace its plastic and
postable materials can
be broken down over time by
bacteria and fungi.
LOLIWARE cups are made of
agar, a substance derived from sea-
weed that forms a gel in the pres-
ence of water. Agar is used in laboratories to
cultivate bacterial colonies and in medicine as
wound dressing. In molecular gastronomy,
agar is used as a jellifying agent for a side
dish such as arugula spaghetti.
In hot water, agar forms random coils in
solution (Fig. 1). In this state, it is easy to put
into molds for shaping. As it cools, agar gels
because hydrogen bonds cross-link galactan
chains (a polysaccharide consisting of galactose monomers). Further cooling consolidates the gel to form a firmer gel that can be
dried to create drinking cups.
Because agar is only water soluble at
95–100 °C, LOLIWARE cups are relatively
stable and can hold soda until you decide
to eat your cup. If you don’t want to eat
your cup, it can also be composted to make
Making edible water
bottles with spherification
In the United States, plastic water bottles
are a huge problem. Every year, we use 50
billion plastic water bottles but only recycle
23% and send the remaining 38 billion water
bottles to landfills. This roughly translates to
every person in the United States throwing
away 119 plastic bottles every year.
Generating new plastic water bottles is
also incredibly costly and energy inefficient:
The amount of oil consumed to make plastic
bottles could fill the gas tanks of 1. 3 million
cars or power nearly 200,000 homes for an
entire year! Last year, the Skipping Rocks
Laboratory in the United Kingdom proposed a
solution to our costly dependence on bottled
water: the Ooho! edible water sphere.
Similar to the LOLIWARE cups, Ooho!
edible water spheres use a seaweed deriva-
tive called sodium alginate (Fig. 2). How-
ever, sodium alginate doesn’t form a gel in
response to boiling water. Sodium alginate
must undergo a chemical process, called
reverse spherification, to form a membrane.
In reverse spherification, calcium lactate
(a common salt used in baking agents and
dietary supplements) is dissolved in water
and added to a cold water bath pre-mixed with
Figure 1. Agar molecules bind together at low temperatures.
What do the skeptics say?