Sea cucumbers and cheese making: Exploring the use of milk coagulant obtained from the digestive tract of Holothuria scabra

Large-scale aquaculture of the sea cucumber Holothuria scabra is
currently being developed in many countries around the world.
The main tissue of the sea cucumber exploited in this industry is
the body wall, mainly exported in its dried form called trepang or
beche-de-mer. The digestive tract of sea cucumbers, including
H. scabra, is therefore largely unused. The aim of this chapter is to
explore the feasibility of making artisanal cheese with coagulant
extracted from the digestive tract of H. scabra. The experiments
were carried out in Madagascar with holothuroids obtained from
the private company Indian Ocean Trepang with cheese production
carried out in collaboration with the Fromagerie Artisanale de
Tuléar. The first step of the experiment consisted of preparing a
milk coagulant from the midgut of H. scabra and comparing its
coagulating potential to commercialized rennet. Each replicate
(n ¼ 5) using the midgut extract from H. scabra demonstrated
coagulation of the milk and the curd obtained was, on average,
23.5% higher in weight than that obtained with the commercialized
rennet. Weight loss after 72 h of draining and maturing was
around 50% for both coagulants. The resulting cheeses were tasted
by 12 volunteers who appreciated both types, eight preferring the
cheese made from the midgut of H. scabra extract because it was
less dry than the one made from commercialized rennet. We
demonstrate that milk coagulation, which is the first step in cheese
making, can be achieved using an extract from the midgut of
H. scabra and most likely with that of other species of sea cucumbers.
The manufacture of milk coagulant may thus be a way to
valorize the typically discarded digestive tracts in harvested sea
cucumbers.