Valorisation of whey 167
value- added products (Smithers, 2015). Can such a transformation also occur
for acid whey? Below we introduce the most common valorisation pathways
for acid whey (including casein whey), drawing on a review of research
articles and company websites.
Animal feed
For decades, using acid whey and sweet whey for animal feed has been one
of the most common uses of whey due to their nutritional properties. Acid
whey is especially suitable for piglets because of the acidity and nutritional
composition. In piglet diets acid whey is mainly a source of energy (milk
sugar) rather than a protein source.
Many Greek yoghurt and cheese manufacturers still pay their milk suppliers to take the acid whey, which they then mix with silage for animal feed
(Smithers, 2015). Although acid whey is a suitable feed, the transport and
storage of liquid whey is costly and barely profitable. Some yoghurt makers
such as Chobani in the US sell it to local farmers for animal feed supplement
(Erickson, 2017b). Chobani has invested in reverse- osmosis filtration technology, which separates the water from the whey using high- pressure systems,
resulting in a more compact by- product that is easier and cheaper to transport
to farms (Erickson, 2017b).
Biogas
Another common application of acid whey is as a substrate for biogas production, where the biogas is used for electricity production. No estimate of the
financial gain for this utilisation could be found. The first environmental gain
of using acid whey for biogas production is the avoided risk of spillage of acid
whey into the environment. The second gain occurs if the electricity produced replaces electricity made from non- renewable sources and thereby
reduces greenhouse gas emissions. Biogas can also be upgraded into pure
methane and fed into the natural gas grid, where it exists. In Switzerland,
several cheese plants have biogas digesters installed onsite (Jelen, 2011).
Alphina Foods (NY) is an example of a company that transports acid whey to
a nearby farm, where it is used in biogas production. Some biogas plants, for
instance in the UK, run entirely on whey.
Bakery
Some research articles examine the use of the acid whey which stems from
the production of the Indian cottage cheese known as paneer, as a bread
ingredient (Divya & Rao, 2010; Paul, Kulkarni & Rao, 2016). They report
that the inclusion of a moderate amount of acid whey did not have any negative influence on the bread quality, while higher amounts increased the
dough proofing time. Research design and results reveal the focus to be on
value- added products (Smithers, 2015). Can such a transformation also occur
for acid whey? Below we introduce the most common valorisation pathways
for acid whey (including casein whey), drawing on a review of research
articles and company websites.
Animal feed
For decades, using acid whey and sweet whey for animal feed has been one
of the most common uses of whey due to their nutritional properties. Acid
whey is especially suitable for piglets because of the acidity and nutritional
composition. In piglet diets acid whey is mainly a source of energy (milk
sugar) rather than a protein source.
Many Greek yoghurt and cheese manufacturers still pay their milk suppliers to take the acid whey, which they then mix with silage for animal feed
(Smithers, 2015). Although acid whey is a suitable feed, the transport and
storage of liquid whey is costly and barely profitable. Some yoghurt makers
such as Chobani in the US sell it to local farmers for animal feed supplement
(Erickson, 2017b). Chobani has invested in reverse- osmosis filtration technology, which separates the water from the whey using high- pressure systems,
resulting in a more compact by- product that is easier and cheaper to transport
to farms (Erickson, 2017b).
Biogas
Another common application of acid whey is as a substrate for biogas production, where the biogas is used for electricity production. No estimate of the
financial gain for this utilisation could be found. The first environmental gain
of using acid whey for biogas production is the avoided risk of spillage of acid
whey into the environment. The second gain occurs if the electricity produced replaces electricity made from non- renewable sources and thereby
reduces greenhouse gas emissions. Biogas can also be upgraded into pure
methane and fed into the natural gas grid, where it exists. In Switzerland,
several cheese plants have biogas digesters installed onsite (Jelen, 2011).
Alphina Foods (NY) is an example of a company that transports acid whey to
a nearby farm, where it is used in biogas production. Some biogas plants, for
instance in the UK, run entirely on whey.
Bakery
Some research articles examine the use of the acid whey which stems from
the production of the Indian cottage cheese known as paneer, as a bread
ingredient (Divya & Rao, 2010; Paul, Kulkarni & Rao, 2016). They report
that the inclusion of a moderate amount of acid whey did not have any negative influence on the bread quality, while higher amounts increased the
dough proofing time. Research design and results reveal the focus to be on