People are getting more interested in what they're eating, but reading a food label will tell you only so much. Some foods -- fresh fruits and vegetables, for example -- don't have ingredient labels.

In a perfect world, food labels would tell you unambiguously and transparently what's inside the package -- what you're really eating. Unfortunately, today's food labels tell only part of the story.

The truth is that there are some ingredients that food makers are not required to list on labels. In other cases, the wording is ambiguous to the point of being meaningless. For example, labels may say "natural color" or "vegetable oil" or "natural flavor." But they don't tell you whether that color comes from a flower or a beetle, or whether the oil is sunflower oil or palm oil (the latter a culprit in deforestation). And nobody knows what "natural flavor" means.

Even where food labels do provide data, it's difficult to put that data into context, or even understand what's being said. For example, if a label says 120mg of sodium per serving, is that too much?

The public's awareness of problems with food comes from a variety of sources. For example, some learned from the documentary Wine From Here that it's legal to add up to 200 specific ingredients to wine, including weird stuff like dimethyl dicarbonate, which chemically sterilizes the wine, or even fish bladders, without having to list them on the label. A bottle of wine can have dozens of strange substances while the label falsely lists "grapes" as the only ingredient.

As with so many things, a bounteous number of standard food ingredients are now manufactured in China, with limited oversight or knowledge about how those ingredients are sourced or made. Chinese food manufacturing is so problematic it has its own Wikipedia page.

Stories about food adulteration abound, from so-called "honey laundering" to counterfeit alcohol.

Demand for better food labeling resulted last week in a new law that requires food producers selling genetically modified organisms (GMO) to label the packaging with that information. The U.S. Department of Agriculture has two years to work out the details, but the outcome will be that GMO-containing food products will be labeled with either a verbal identification, a symbolic one or a QR code, with the food producer choosing which kind of identification to make.

This is great news for the beleaguered QR code, by the way. It's probably going to be a major way that GMO foods are labeled, which gives apps that support QR codes a new reason to exist.

One approach to tech that informs about food is to build massive databases of knowledge about foods and food products.

The Sage Project is an initiative by designer and developer Sam Slover. The idea is to create food ingredient labels in the cloud, which can be accessed on the web or via a mobile app (the web version is now live and the mobile apps are coming soon, according to Slover). (You can listen to my interview with Slover here.)

Sage gets food information mainly from the manufacturers. Interestingly, Slover said companies were initially reluctant to provide the information but recently have been clamoring to do so. Separately, the food industry is reportedly discovering that unless food companies provide ingredient information, the public will seek it out from more reliable sources offering more transparency.

Sage lists food types (for example, "mandarin oranges") and food products (such as Theo Chocolate's Organic Fair Trade Orange (70%) Dark Chocolate Bar) in its nearly 20,000-item food database.

When you search for an item, you get nutritional information, fitness information (for example, an estimate of how much exercise you would need to burn off the calories) and, crucially, personalization. For example, if you tell Sage upon signup that you're a vegan, following the paleo diet or don't want any GMOs, Sage will warn and inform you with every search.

When possible, Sage will also tell you the source of the food or ingredient.

Slover told me that the mobile apps will take advantage of bar and QR codes to automate product searches.

The company also intends to explore food testing so its ingredient database reflects what's actually in the products, rather than what the food makers claim or what the labels list.

Another option, an iOS and Android app called IPIIT, also uses the bar code to call up information about food products. You can personalize it by adding specific information about any allergies or dietary restrictions or preferences. By scanning the product, you get a green light if it's OK to eat. Nice!

Other companies offer similar apps, and they often are helpful. But what consumers really need is a way to directly detect or test what's in the food that's right in front of them.

Handheld scanners that detect food properties

A $199 product called the Nima is a handheld scanner that can detect gluten in food.

To use it, you put some of the food in question into a disposable capsule and place the capsule into the triangular Nima scanner. Within two minutes, you get a ruling on whether any gluten is present in the food.

Another scanner called Tellspec costs $499 and uses a laser to evaluate food ingredients. If you zap a food with Tellspec and wait about 30 seconds, you'll get an estimate of calories, carbohydrates, protein, fats, fiber and glycemic load. The associated app also tries to alert you to any known allergens it detected.

Yet another product called the SCiO, which the company calls the "world's first pocket molecular sensor," and which should ship in December, can theoretically perform a range of feats, from detecting nutrients in foods (and logging them for you in an app) to checking the amount of water in the leaves of your houseplants. The SCiO scanner will cost $249. In its current incarnation, the SCiO product isn't quite ready for the consumer public, but the company promises additional apps that will make it more useful for shoppers.

The trouble with scanners

This scanning technology is promising. Even the first generation of scanners now hitting the market can already provide some insights.

But the biggest problem with the scanners is that you can't scan most foods in their entirety. For example, you can detect the ingredients in, say, ice cream because all the ingredients are mixed together evenly. But you can't scan a sandwich or a chocolate chip cookie or a salad.

You also can't scan products that are inside packages; you can't scan the ice cream in the store without opening the lid, which is surely a shopping faux pas.

Clearly, the ultimate food consumer product would be a hybrid of everything I've mentioned in this column -- a food scanner and a bar code and QR code scanner backed by a massive, detailed database that combines data from food producers, crowdsourced data, and data from independent organizations that do testing on food products.

Until then, people will have to get by on their own, downloading or buying the apps or scanners they can and piecing together the truth about what's really in the food we eat.

Still, today's new technology is far better than yesterday's reliance on incomplete, ambiguous food labels.