Do I need to heat treat hummus?
“Just to clarify, heat treatment is not the same as cooking. By heat treatment, we mean a short controlled treatment of the final product at a predetermined temperature. To make hummus, the chickpeas always needs to be cooked but there is no need for heat treatment if the hummus is refrigerated and eaten within a few days.”
How can I extend the shelf life of chilled hummus?
“You can add lemon juice to reduce the pH and add preservatives, but these usually only extend the shelf life for a couple of weeks in chilled storage. As an alternative, you can pasteurize the hummus and this can extend the shelf life to up to 6 weeks in chilled storage. In that case, there may be no need to add preservatives, giving your product a ‘clean label’. To achieve a long shelf life at room temperature, a UHT treatment is necessary. A retort process is another alternative where the product is heat treated inside the package.”
How is UHT treatmentof hummusdifferent from pasteurization?
“It is all about commercial sterility. UHT stands for ultra high temperature and means that the food is heat treated at a temperature above 135°C for a short time. This will kill all bacteria including their spores, so there are no microorganisms left to grow in the product during room temperature storage. In contrast, pasteurization reduces the microbiological load but some bacteria survive and the product needs to be stored under refrigerated conditions to control the growth rate. Commercial sterility enables storage at ambient temperatures for 6 to 18 months. This is not possible with the temperatures achieved during pasteurization. One advantage we have found with UHT treatment is that about a third less chickpeas are needed to make the same volume of hummus, giving savings in raw material costs. This could be due to increased gelatinization at higher temperatures.”
How can heat treatment of hummus be optimized?
“Batch pasteurization is possible, but it takes a longer time to heat and cool in a batch while the extended heating process creates a high heat load on the product. This can have a negative impact on quality. In addition, batch pasteurization reduces the overall production capacity. In contrast, a continuous heat treatment optimizes the heating process and heats the product rapidly to the desired temperature and keeps it there for exactly the necessary time, which is usually no more than a couple of minutes. Cooling the hummus down to refrigeration temperatures is also done much more efficiently in a continuous processing line.”
What heating system do you recommend for hummus production?
“The choice of heating system depends on the required capacity, intended storage temperature and shelf life.
Batch pasteurization is good for small to medium-sized plants when the product is intended for chilled storage for up to 6 weeks. To achieve a long shelf life with batch pasteurization, the transfer between the batch system and filling machine needs to take place under good hygienic conditions to minimize the risk of recontamination.
Continuous pasteurization is done in a closed system with controlled transfer to the filling machine so the risk of recontamination is minimal. The product is intended for chilled storage.
Continuous UHT treatment gives a commercial aseptic product which can be stored at room temperature. A UHT processing line requires an aseptic transfer and an aseptic filling machine.
The recommended heat exchanger for a continuous hummus processing line is either a scraped surface heat exchanger or a coiled tubular heat exchanger.”
Questions about hummus production?
If you have any other questions about hummus processing,you are welcome to contact us
