Due to the environmental impact of animal meat such as beef, pork and poultry, a need for alternative protein sources and meat substitutes is growing. Insects seem to provide the optimal alternative

Bruins, M.E.

Hua, K.N.P.

Roland, W.S.U.

Tonneijck, L.

English

NARCIS 

Mealworm Products with Custom-made Texture

Wageningen Yield 

108     THE WORLD OF FOOD INGREDIENTS OCTOBER/NOVEMBER 2017
What seemed like a futur-istic idea only recently has now become reali-
ty: insects as food ingredients. More 
and more food companies are look-
ing into the possibilities of using 
insects as ingredients in their food. 
Experts at Wageningen University 
& Research are making the choice 
of suitable insect species easier with 
their inventory of nutrients. Their 
research shows that yellow meal-
worm paste can be produced with 
diverse textures, which offers possi-
bilities for the development of prod-
ucts like insect burgers and spreads. 
A growing global population is 
creating a growing demand for pro-
teins and meat. Due to the environ-
mental impact of animal meat such 
as beef, pork and poultry, a need 
for alternative protein sources and 
meat substitutes is growing. Insects 
seem to provide the optimal alterna-
tive. The amino acid composition of 
many edible insects is similar to that 
of meat, especially when it comes 
to essential amino acids. On top of 
that, insect lipids are composed of 
a high content of unsaturated fatty 
acids, meaning that they are health-
ier than conventional meat, which 
is rich in less healthy saturated fat-
ty acids. Furthermore, the environ-
mental impact of insects, such as 
feed conversion rate, ammonia and 
methane emissions, and CO2 foot-
print, is significantly lower than that 
of usual livestock. 
Choice of Insects
Grasshopper, larvae of black soldier 
fly or mealworm beetle? Of all the 
edible insects available, which one 
should we choose as a food or food 
ingredient? Insects are very diverse, 
and within each species, there is a 
large difference in composition de-
pending on their developmental 
stage: eggs, larvae, pupae and adults. 
Depending on the intended ap-
plication, a high, medium, or low 
content of protein, fat, or chitin 
is advisable and should direct the 
product developer’s or scientist’s 
choice. When looking for an insect 
that would be used as a whole or as 
a flour or paste, it is more impor-
tant to choose an insect that is rich 
in both protein and fat, and low or 
moderate in chitin, as chitin-rich 
parts of the insects are uncomfort-
able to chew on. 
Insect Inventory
To assist in making the right choice, a 
Wageningen University (WUR) team 
created an inventory of hundreds of 
edible insects reported in scientific 
literature and plotted their contents 
of protein, fat and chitin. An exam-
ple can be seen in figure 1, which 
shows protein and chitin contents 
in different insects. The highlight-
ed section in this figure shows the 
top 20 edible insects that are high 
in protein and low in chitin concen-
trations. One of the most favorable 
insects from this group is the silk 
worm, Bombyx mori, which makes 
a great choice for protein extraction, 
with almost 70% protein. The  silk 
worm can also be eaten as is. For ex-
ample, in Vietnam, these side-prod-
ucts of silk production are consumed 
with spices and sauce. Another in-
teresting insect is the yellow meal-
worm, Tenebrio molitor – which is 
the larvae of the mealworm beetle, 
which can be used as a whole with a 
reasonable fat (circa 40%) and pro-
tein (circa 50%) content, which is 
low in chitin. 
Insect Product Innovation
Keeping the environmental and nu-
tritional reasons in mind, edible in-
sects seem to be an ideal alternative 
to meat, if it weren’t for the legs and 
the wings and the creepy-crawly at-
tributes that make them less accept-
able as food for Western consumers. 
Then again, almost one-third of the 
world's population eats insects on a 
regular basis. The market for insects 
is emerging. What kind of com-
mercial insect products have been 
launched in recent years? 
As the so-called worms, which are 
in fact the larvae of insects, have a 
high protein and fat content and are 
low in chitin, this group became the 
focus of our Innova Database search. 
We basically found three catego-
ries of worm products: 
NEW INGREDIENT SOURCES
Mealworm Products  
With Custom-Made Texture
Due to the environmental impact of animal meat  
such as beef, pork and poultry, a need for alternative  
protein sources and meat substitutes is growing.  
Insects seem to provide the optimal alternative.
 by Wibke S.U. Roland, Lenka Tonneijck-Srpova, Nam-Phuong Humblet-Hua and Marieke E. Bruins
Figure 1: Edible insects sorted by protein and chitin content.
Insects.indd   108 19-10-2017   17:54:46
110     THE WORLD OF FOOD INGREDIENTS OCTOBER/NOVEMBER 2017
•	 Dried	whole	worms		
as	pet	food;
•	 Dried	and	seasoned	worms,		
as	snacks	or	seasoning,	and;
•	 Processed	worms	as	ingre-
dients	in	spreads	and	meat	
alternatives.	
The	first	category,	pet	food,	is	ne-
glected	here	in	this	particular	food	
context.	The	second	category,	snacks	
and	seasoning,	has	the	smallest	por-
tion	size	and	the	highest	price	per	kil-
ogram.	For	example,	flavored	meal-
worm	crisps	used	as	a	fancy	snack	
cost	more	than	€150/kg,	with	por-
tion	sizes	of	circa	20g.	These	prod-
ucts	are	clearly	niche	products,	as	
they	are	too	high	in	price	or	are	con-
sumed	in	too	little	amounts	to	be	
relevant	for	nutrition.	The	third	cat-
egory,	processed	worms	as	ingredi-
ents,	is	very	interesting	from	a	nu-
tritional	point	of	view.	Additionally,	
the	worms	are	unrecognizable	in	
food	products,	which	will	increase	
the	chance	of	acceptance	by	west-
ern	society.	In	mealworm	spreads,	
the	main	components	are	vegeta-
bles	and	vegetable	oil,	whereas	meal	
worms	account	for	only	4-6%	of	the	
ingredients.	Meat	alternatives	such	
as	schnitzels,	vegetable-based	burg-
ers	or	nuggets	contain	14%	buffalo	
worm	which	is	relatively	high,	as	it	
is	listed	as	a	second	ingredient	after	
water.	These	non-vegetarian	meat	al-
ternatives,	therefore,	represent	prod-
ucts	with	a	more	substantial	insect	
content.	Overall,	the	number	of	in-
sect	food	products	is	quite	small.	As	
for	making	insects	substantial	replac-
ers	of	our	common	animal	proteins,	
processed	worms	as	ingredients	in	
spreads	and	meat	alternatives	are	
the	most	promising.	
Technical Challenges
In	order	to	use	insects	as	food	ingre-
dients,	among	others	(see	outbox),	
two	hurdles	have	to	be	overcome:	mi-
crobial	safety	and	browning.	Brown-
ing	of	mealworms	occurs	due	to	the	
presence	of	the	enzyme	polyphe-
noloxidase.	WUR	performed	ex-
periments	with	yellow	mealworms	
(Tenebrio molitor),	addressing	these	
two	aspects,	followed	by	an	investi-
gation	of	texturization.	
In	our	experiments,	different	
blanching	and	high-pressure	treat-
ments	–	a	relatively	new	mild	pres-
ervation	technique	–	were	tested	on	
whole	mealworms.	The	mealworms	
were	then	ground	into	a	paste	in	or-
der	to	evaluate	the	effect	of	the	treat-
ments	on	browning.	The	best	condi-
tions	that	prevented	browning	were:
Short	blanching	with	a	peak	tem-
perature	of	80°C,	or;
High-pressure	treatment	with	
pressures	of	>	400	MPa	(4,000	bar).	
The	side	effect	of	blanching	is	
a	softly	textured	mealworm	paste,	
whereas	high-pressure	treatment	re-
sulted	in	a	harder	and	drier	texture.	
Browning	could	also	be	prevented	
by	the	use	of	air-tight	packaging.
Custom-Made Texture 
Combining	the	results	of	blanching	
and	high-pressure	treatments	allows	
us	to	tailor	the	texture	of	the	meal-
worm	product.	For	a	spread,	the	
color	should	be	light	and	the	tex-
ture	soft.	Therefore	blanching	is	the	
best	method.	
For	a	burger,	browning	and	a	firm-
er	texture	are	desirable,	so	the	ad-
vice	is	high-pressure	treatment	at	
400	MPa	(4,000	bar).	Another	op-
tion	would	be	no	treatment	at	all.	
In	this	case,	microbial	safety	can	be	
assured	by	heating	the	mealworm	
burger	in	the	pan.	
A	burger	should	be	somewhat	
crumbly	and	release	some	mois-
ture,	but	not	too	much.	Both	meal-
worm	burgers	meet	these	require-
ments.	A	pâté	type	of	texture	can	also	
be	achieved	with	mealworms	when	
high-pressure	treatment	at	500	MPa	
(5,000	bar)	is	applied.	
Compared	to	real	pâté,	which	
is	mostly	made	of	pork	meat,	liver	
and	fat,	an	additional	advantage	is	
that	the	surface	layer	stays	fresh	for	
at	least	3	weeks.	In	laboratory	tests,	
high	pressure	treated	mealworms	
showed	an	appealing	orange/light	
brown	color,	and	the	aroma	of	meal-
worm	paste	was	savory,	with	a	mush-
room	and	nutty	note.	Upon	baking,	
the	aroma	even	intensified.	
These	properties,	combined	with	
excellent	nutritional	values,	sup-
ports	our	belief	that	mealworm	
paste	has	a	future	as	a	food	ingre-
dient	on	the	non-vegetarian	meat	
replacer	market.t
t Aspects of Insects as Food Ingredients
In addition to nutrient content, other aspects of insects 
have to be taken into account for their use as food 
ingredients as well: 
•	 Productivity	and	possibility	for	mass-rearing
•	 Insects	should	feed	on	substrates	free	from	pathogenic	microor-
ganisms	and	toxic	compounds,	as	they	might	accumulate	them.	
•	 Allergenicity	–	The	allergenicity	of	insects	is	an	aspect	which	
has	not	sufficiently	been	researched	yet	for	most	species,		
and	which	should	be	labeled	when	known.		
People	allergic	to	crustaceans	or	house	dust	mites		
might	be	allergic	to	some	insects	as	well.
•	 Legal	status	–	At	the	end	of	2015,	the	EU	decided	that	insects	
have	to	go	through	a	Novel	Food	regulation	process,		
although	national	exceptions	do	exist.t
Figure 2: Baked mealworm paste is dark brown for fresh and  
250-300 MPa, compared to light brown for 400-500 MPa  
and light brown for blanched treatment.
Wibke Roland, Lenka Tonneijck-
Srpova, Nam-Phuong Humblet-
Hua and Marieke Bruins conduct 
applied research in the Food 
Technology group of Wage-
ningen Food and Biobased 
Research, mainly on request of 
food companies. The mealworm 
research was performed within 
the STW In2Food project – Pro-
duction and valorization of high 
proteins from insects. For more 
information about product  
development with insects,  
please contact Marieke Bruins: 
marieke.bruins@wur.nl
Insects.indd   110 19-10-2017   17:58:12


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Mealworm Products with Custom-made Texture

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