Spoilage of fruit juices causes huge economic damage each year. Now, creative students at the Technion-Israel Institute of Technology in Haifa have harnessed viruses found in the environment of fruit trees to prevent this phenomenon. 

The culprit is ACB, or Alicyclobacillus acidoterrestris, a bacterium found in the ground in which fruit trees grow and in all parts of the tree itself. Although it is not harmful to humans, it releases a natural substance called guaiacol into the juice, spoiling its taste and smell. This occurs in a broad variety of juices, including orange, mango, pear, grape, tomato, and others, and leads to the loss of large quantities of juice, as well as massive financial losses

The development earned the students from the Technion’s Faculties of Biotechnology & Food Engineering, and Biology first prize in a competition held as part of the MicroBiome-Push project conducted within “Food Solutions,” an educational program of the European food consortium, EIT Food. 

Prof. Marcelle Machluf, dean of the Faculty of Biotechnology and Food Engineering, said that “international projects such as this are the very essence of the faculty and its way of teaching future generations to think outside the box, be entrepreneurial and broaden the knowledge we are able to provide in the classroom.”

The goal of the competition was to solve problems in the food sector by bringing together companies in the food industry (PepsiCo, Puratos and Agricolus) with undergraduate and graduate students from four universities – the Technion, the University of Turin in Italy, the University of Reading in the UK and the University of Helsinki in Finland. Nine groups of students competed, including two from the Technion.

The two Technion groups chose challenges posed by the global PepsiCo corporation. The first was to solve the problem of spoilage of fruit juices, while the second was to use potato peels that are left over from the production of potato chips. The groups were accompanied by four mentors from the biotechnology and food engineering faculty – Prof. Yoav Livney, who headed the Technion’s activity in the project, Prof. Yechezkel Kashi, Assistant Prof. Avi Shpigelman and Associate Prof. Uri Lesmes. Members of the winning team, the Microbes, were Itzik Engelberg, Alon Romano, Leechen Mashiah and Rachel Bitton, and members of the second Technion group, Biomy, were Omer Sabbah, Yuping Kao, Or Shapira, Michael Buzaglo and Lior Kaufman

According to the mentors, “the two Technion teams did an amazing job, and despite the limitations posed by COVID-19, they succeeded in creating original, effective solutions. What’s more, they presented the viability of the ideas to the corporations, and showed their inherent business potential.” 

The Microbes chose to address the acute problem of spoilage of natural fruit juices, which in the US alone causes damage estimated at around $32 million each year.

In the course of evolution, the bacterium has developed high resistance to hostile environmental conditions, enabling it to also survive the processes involved in juice production – cleaning, extraction, pasteurization and filling. As a rule, pasteurization is efficient in destroying bacteria that are harmful to health or adversely affect juice quality. But this is not the case with ACB, since the juice cannot be heated to higher pasteurization temperatures or for a longer time without compromising its quality and nutritional values. PepsiCo has been looking for a creative solution that will prevent this harmful phenomenon.

“Since the problem has its origins in nature – a bacterium that lives in the soil – we looked for a natural solution,” explained doctoral students and team members Romano and Engelberg. “After all, nature is a ‘laboratory’ that has been perfecting its solutions for billions of years, and our assumption was that solutions that developed in the evolutionary process could also serve us as a solution for dealing with the problem of ACB in the food industry.”

After much searching and numerous analyses, the choice was a bacteriophage, a virus that infects bacteria naturally and in a very specific way. Bacteriophages are abundant in nature, and following strenuous research, the group succeeded in isolating and identifying a bacteriophage that destroys the harmful bacteria. It takes just a small dose to efficiently eliminate the bacteria, and because it does so selectively, it is safe for use and it has no harmful effects on human health.

The competition focused on finding solutions to challenges related to the natural microbiome, the microorganisms populating a particular environment. The microbiome includes bacteriome, virome, and mycobiome (which represent, respectively, the assemblages of bacteria, viruses, and fungi), and the winning solution in fact harnesses a specific virus present in the phytosphere (the microbiome of the plant and its environment) to combat a specific bacterium from that same environment. 

The fact that this is a natural, inexpensive solution that does not involve genetic engineering is expected to expedite the application of the technology in juices and to reduce the need for preservatives. In addition, the addition of the virus to the juice does not affect it in terms of religious dietary laws – Jewish (kashrut) and Islamic (halal).

The second Technion group, Biomy, also tackled a far-from-simple challenge and developed the PotatALL concept, which includes a number of creative solutions for treating potato peels left over in the process of producing potato chips. Team members presented a process to produce from the peels a raw material used to create eco-friendly packaging, as well as a dip made from potato peel. This comprehensive and creative solution also met with the judges’ praise. The intention is for the dip to be served in small packs similar to ketchup, along with fries, and to package it in the eco-friendly packaging made from the peel. The solution provides a perfect way to fully utilize all parts of the potatoes while mitigating the environmental impact.