Hot Stuff, Spring 2000

Not-so-hot chile

Science doesn't always have to be so serious.

Take the recent winners of the Ig Nobel prizes, which are given annually at Harvard to celebrate the unusual and honor the imaginative.

The winner of the Ig Nobel for physics calculated the optimal way to dunk a biscuit. The environmental protection winner invented a self-perfuming business suit. The peace prize went to the inventors of a flame-throwing automobile burglar alarm.

NMSU is home to a 1999 Ig Nobel laureate, chile breeder Paul Bosland, who received the biology prize for breeding a spiceless jalapeño.

"We give out 10 of these every year for achievements that cannot or should not be reproduced," says Marc Abrahams, editor of the Annals of Improbable Research and host of the annual ceremony. "And when you think about that-cannot or should not be reproduced-that doesn't say anything about whether something is good or bad."

Abrahams says wacky research gets people interested in science. "This is our really sneaky approach to getting people interested in science and getting them to understand that you don't have to be a genius to understand this stuff," he says.

In February, Abrahams visited the NMSU campus to get a firsthand look at Bosland's greenhouse research and to give a seminar in the College of Agriculture, Consumer and Environmental Sciences.

"Paul Bosland did something that we heard about from a number of sources, and when we first heard about it, it sounded perfect," Abrahams says. "It sounded crazy. Someone has come up with a variety of jalapeño pepper with no spice. Well, it is crazy, but it is wonderfully crazy."

Bosland maintains that while a mild jalapeño sounds like an oxymoron, there is a good reason for his research.

"In the food industry, there is a broad scope of salsa-making-we have salsa that is mild, medium and hot," he said. "If you want to make a mild salsa and all of your jalapeños are hot, well what can you do?"

One option, he explains, is to add more bell pepper or tomato, which changes the salsa's flavor.

"But if you have a mild jalapeño, then you can mix that in to make mild or medium salsa without compromising the flavor," Bosland says.

Having bred a mild jalapeño, Bosland's next step is developing a variety that has "absolutely no heat." In the greenhouse, he has a number of jalapeño selections that he is testing for no heat and good flavor.

Bosland says the response to winning the prize has been two-edged. Some people think he has "sold his soul to the devil."

"On the other hand, we offered a free seed sample and literally got thousands of letters from folks wanting to try this in their gardens," Bosland says

Get ready for ripe red

When it comes to nutrition, succulent red chile is giving chile lovers a reason to cheer.

NMSU researchers have found that the ripe red fruit of New Mexican-type chile contains three to four times more vitamin A, C and E than the green fruit.

"We usually use fresh green chile or dried red chile in our recipes, but we should try to find more uses for the succulent or ripe red chile to maximize the nutritional value," says Marisa Wall, a postharvest physiologist with NMSU's Agricultural Experiment Station.

Wall's primary interest wasn't in the nutritional value of chile. Instead, she was looking for ways to develop chile varieties with higher carotenoid or pigment levels. The yellow, orange and red colors of chile are attributed to the carotenoid pigments produced during ripening.

"The higher the carotenoid level, the more value red chile has to the processing industry as a natural source of food coloring or as a nonpungent spice like paprika," she explains.

But high carotenoid levels also can mean high nutritional value. Beta-carotene, for example, turns into vitamin A during digestion. Also, vitamins A, C and E are rich antioxidant vitamins, which may protect against cancer.

In a recent study, Wall analyzed the carotenoid content of 25 fresh and 40 dried chile samples.

She found that 100 grams of fresh Greenleaf Tabasco, Pulla, Guajillo, NuMex Conquistador, Ring-O-Fire and Thai Dragon contain more than 100 percent of the Recommended Daily Allowance of beta-carotene for adults.

Of the dried chile varieties tested, two paprika varieties developed at NMSU came out in the top five for beta-carotene and total carotenoid content. "We found that our chiles are already very high," Wall says. "But we did find one pasilla type, which had the highest total carotenoid content, that we're working to incorporate into our breeding program."

In another study, which was published in the Journal of Agricultural and Food Chemistry, Wall looked at how vitamin C and E content changed as New Mexican chiles ripen from green to red.

Nutritional value aside, these two vitamins are important because they can help prevent the carotenoid pigments from oxidizing or degrading in chile.

Wall found that the highest levels of vitamin C and E occurred when chile was at the red succulent and partially dry stages of ripening.

"This information is useful for plant breeders and food scientists who are working to maximize the nutritional content and carotenoid stability of fresh, processed and dehydrated chile."

But consumers should take note, too, and start adding fresh red chile to their diets, Wall adds.

Infrared photos focus on stressed out chile

Long before growers in the Mesilla Valley see any signs of trouble in their chile fields, infrared photographs may be able to detect stressed plants.

Vegetation strongly reflects infrared radiation, which falls just outside the visible range of the light spectrum, says Robert Sanderson, a pest management specialist with NMSU's Agricultural Experiment Station.

"If vegetation is stressed for some reason, whether it's water, insect or disease stress, it sends out different infrared reflectance," Sanderson says. "We wouldn't be able to visually see this immediately. But by looking at pictures of the infrared reflectance, we might be able to detect some of that stress in the crops."

For several years, Sanderson has been working to combine precision farming techniques with aerial infrared photography and technologies like global positioning satellite (GPS) systems and geographic information systems (GIS).

GPS allows pinpointing of positions on the globe, while GIS software allows layering of information and maps.

In precision or prescription farming, farmers can tailor decisions about fertilizer and pesticide use to small sections of a field.

"Crop performance may vary considerably between fields and within fields due to factors such as fertility, drainage, soil, salinity and pest problems," Sanderson explains.

By comparing the infrared photos from week to week, he may be able to measure stand establishment, monitor crop development, detect insect and disease outbreaks and determine field productivity.

Sanderson's work is part of a new effort called the Center for Applied Remote Sensing in Agriculture, Meteorology and Environment, which is a collaboration with the U.S. Army Research Laboratory, NMSU's Physical Science Laboratory and the Directorate of Environment at Fort Bliss.

"Chile is one of our priorities," Sanderson says. "It's a perfect test case."

In 1999, the researchers worked out the practicality of monitoring chile fields and pinpointing problem areas with the infrared photos.

This year, Sanderson will take photos of stressed chile fields identified by other NMSU scientists and Cooperative Extension Service specialists. This will help researchers learn how common problems look on infrared images.

In the future, Sanderson hopes to provide chile growers with timely information so they can make quick decisions as conditions change. "Farmers want the information now, so that they can make adjustments as they drive along the field. They don't want to wait three or four weeks before they see the picture or before they know there's a problem."

Waste not the chile

Chile lovers may be horrified to know that green chile processing in New Mexico leaves behind 15,000 tons of leftovers annually. Granted, it's 15,000 tons of peels and seeds-but what a waste.

NMSU food scientists are trying to rectify the situation.

"A little bit of the byproduct from chile processing goes to cattle feed, but much of it ends up in landfills," says Lisa McKee. "We wanted to find some way to put the leftovers to use."

McKee and former graduate student Naoko Matsuda decided to find out if the peels and seeds could be used as a source of fiber in foods.

In an initial study, the researchers dried and ground the byproducts. They ended up with chile fiber that looked a bit like oat bran. Analysis of the product indicated a total dietary fiber content of about 80 percent, much higher than oat bran's 8.2 percent and rice bran's 27.4 percent.

"It also turned out to be fairly high in soluble fiber, which is the type of fiber that you hear a lot about in the news for its ability to reduce cholesterol levels," McKee says.

The researchers next needed to check if the chile fiber was safe for use in food products. "Since it is a byproduct that sometimes ends up on the floor, we were pretty sure there was going to be a problem with microbial levels," McKee explains.

Indeed, the microbial levels were high, but there were other problems as well. "First, green is not a particularly good color for a fiber source that people are going to put in food products. Second, there was some residual pungency that might not be desirable in an ingredient."

In a second study, McKee worked with another graduate student, Alan Wright, to consider different sterilization methods, such as irradiation and extraction with acetone, to reduce the microbial levels.

All the sterilization methods worked well. "We found that the acetone extraction also took out a significant amount of the pungency and reduced the color content," she says. "That left us with a more bland and colorless product, which is what we were hoping for."

Next, McKee will test the chile fiber in a variety of food products from stews to baked goods, looking for the best use of her chile leftovers.