Newsletter: December 11, 2018

Researched and written weekly by the editorial team of Food Technology magazine, the IFTNEXT Newsletter explores what are, arguably, the next big things in the science of food through original reporting of scientific breakthroughs, leading-edge technology, novel food components, and transdisciplinary R&D.

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Cotton SeedEdible cottonseed receives regulatory approval
More than two decades of dedication paid off for Texas A&M University professor Keerti Rathore when he received word this fall that the genetically engineered cottonseed he and his team developed has been deregulated. Deregulation by the U.S. Dept. of Agriculture’s (USDA) Animal and Plant Health Inspection Service (APHIS) paves the way for use of the transgenic cottonseed as a human food ingredient and significantly expands its potential animal feed applications to include poultry and fish. The researchers’ work revolves around creating a cotton plant with seeds that do not contain the level of a poisonous substance called gossypol that regular cottonseeds contain. (Gossypol is not toxic for ruminant animals such as cows, so livestock feed is currently the main use for cottonseed.)

“We have turned off a gene that encodes an enzyme involved in the biosynthesis of gossypol using a gene-silencing technology called RNAi,” says Rathore. “It was a combination of the right gene-silencing technology, the right target gene to be silenced, and a strict seed-specific promoter (that allows silencing only in the seed) that made the Ultra-Low Gossypol Cottonseed (ULGCS) possible.”

It was important to reduce the levels of gossypol only in the seeds because in the leaves, flowers, and stocks of cotton, it plays a valuable role, defending against pests and pathogens. Although most people think of cotton in terms of its fibers, which are used in creating fabric, the plant yields about 1.6 pounds of seed for every pound of fiber, and the seeds have a protein content of 23%. Rathore says that the seeds could be ground into a flour-like powder and used as a protein ingredient in food products. He also sees potential for the seeds to be roasted and seasoned for snack .

There have been many setbacks and hurdles over the course of the 22 years that Rathore has devoted to this research, but he has remained determined, inspired by the support of his former colleague Norman Borlaug and his belief that low-gossypol cottonseed could make a difference in millions of lives. “It was the potential utility of the ULGCS in terms of making available enough protein to meet the basic requirement of more than 500 million people that kept us going,” says Rathore. “Also, growing up in rural India as the son of a doctor, I had witnessed the consequences of hunger and poor nutrition in the health of his patients.

“Somewhat late in my career, I transitioned from basic science to biotechnology because I saw that genetic engineering has the power to solve many agricultural and food security problems,” he continues. “Certainly, since 2006, U.S. cotton farmers, through Cotton Inc. funding, have supported my work. Without this funding, we would have stopped after our first publication in 2006. The loyalty and dedication of a few people in my lab certainly helped. We were also inspired by Dr. Norman Borlaug, “the Father of the Green Revolution,” who was in my department at Texas A&M until his death. He shared our vision of unlocking the tremendous nutritional value of global cottonseed output and encouraged us to continue even when funding was very tight.”

Regulatory hurdles remain. Rathore says that the researchers submitted petitions to both APHIS and the U.S. Food and Drug Administration (FDA) at about the same time last fall. The APHIS approval means that farmers are free to grow the transgenic cotton, but FDA approval is required before it can be used in human food and as feed for non-ruminant animals such as chicken, fish, and pigs. “FDA is usually slower than APHIS, but we are very hopeful that we will get an approval some time next year,” says Rathore. He adds that he sees poultry and aquaculture species as the two biggest markets for ULGCS.


Chocolate Milk
Salivary proteins may influence food choices
Saliva contains enzymes that begin the digestion process, and it also helps us to taste food. Scientists recently discovered that proteins in saliva go beyond helping us taste food to actually influencing how the food tastes, which in turn could influence what foods people willingly choose to eat.

Proteins released by salivary glands interact with taste receptors in the mouth and flavor compounds in foods. Some are thought to impart astringent taste sensations that people might experience when eating foods such as red wine and certain types of chocolate. Research presented during the 256th National Meeting & Exposition of the American Chemical Society explained how scientists have gained valuable insights into interactions of the salivary proteins and food.

“We found that feeding people chocolate milk, which contained polyphenols (the healthy, but nasty tasting stuff in chocolate), changed the makeup of their saliva,” says Cordelia A. Running, assistant professor of nutrition science and food science at Purdue University. “Some of the changes could mean that these polyphenols might taste less nasty in the long run. This could explain why some people acquire tastes for certain foods, but also could be a useful message for people: that maybe healthy food doesn’t have to taste bad—at least not forever.”

Put simply, the data suggest that regular exposure can make bitter foods more acceptable, says Running’s fellow researcher, Ann-Marie Torregrossa, assistant professor of psychology at the University of Buffalo. “If someone regularly eats a diet with lots of plants, those plants likely taste better to them than someone new to the diet,” says Torregrossa. “If a person is switching to a plant heavy diet and is struggling with the taste, it may be important to understand that it will likely get better.” 

The current research grew out of previous studies that examined diet and salivary proteins in rats. In that research, scientists found that diet alters the salivary protein profile (called the induction phase) and then the salivary proteins alter the taste of food, i.e., make the bitter tastes more acceptable (called the acceptance phase), explains Torregrossa. “We have examined the acceptance phase by looking at both the acceptability of a bitter solution after salivary proteins have been altered and by looking at the firing of one of the taste nerves when the bitter is paired with salivary proteins from a donor animal. In both cases having the right salivary protein profile made the bitter appear less concentrated.”

The researchers hope that what they learned may one day help consumers maintain a healthier diet. “As we figure out how exactly these proteins in spit are related to the flavor, we might be able to figure out ways to change people’s spit to make healthy food taste better, or we might be able to figure out how to use food ingredients to mimic the functions of those proteins in spit, so that the food itself helps those flavors taste better,” says Running.


SweeperRobot detects and harvests ripe sweet peppers
The agricultural industry is experiencing a shift from manual labor to automation. While humans are still a big part of the labor force, more robots are coming online. One such robot is SWEEPER, which is billed as the world’s most advanced sweet pepper harvesting robot.

SWEEPER, which was developed through a collaboration of scientists from Israel, the Netherlands, Sweden, and Belgium, is designed to operate in a single-row cropping system with non-clustered fruits and minimal leaf occlusion where it detects ripe produce using computer vision. The robot made its debut at the Research Station for Vegetable Production at St. Katelijne Waver in Belgium.

“The SWEEPER robot is a significant step towards fully automated agriculture, which would free growers from their dependence on massive amounts of manual labor,” says Boaz Arad, one of the scientists and a PhD student at Ben-Gurion University of the Negev. “This dependence is a specifically pressing concern for pepper growers, as the amount of labor required during peak harvest season is quite disproportionate to that required during the remainder of the year. Since the demand for labor is sporadic, hiring has become increasingly difficult for growers over the past years.”

Arad adds that the autonomous harvesting of sweet peppers is notable due to the intricacies of the harvesting process. Many crops can be pulled or twisted off their vines, such as apples, or shaken off, such as blueberries and olives, whereas sweet peppers require delicate handling and accurate cutting, he adds.

SWEEPER currently can harvest ripe sweet peppers in 24 seconds with a harvest success rate of 62%, according to information provided by Ben-Gurion University of the Negev. The scientists are now working on ways to increase the robots’ speed and harvest success rate. “Ideally, the SWEEPER robot should be able to match or exceed the performance of human harvesters,” says Arad. “While we’re not quite there yet, we’ve learned a lot during the project, and have already developed quite a few improvements that could be implemented in the next iteration of the robot. If all goes well, the commercial partners in the consortium will integrate these and other improvements into a system which will be made commercially available.”