William of Occam or Ockham or Ockingham, the fourteenth century English philosopher and monk, is credited by some with the invention of the scientific method in his admonition that it is vain to multiply causes needlessly. What he meant was, that if two equally consistent theories can explain the same set of facts, the simpler one is to be preferred. His insight has proved to be one of the main pillars of scientific enquiry. If one is willing to include a sufficient number of variables one can "prove" anything, but the hallmark of great scientific insight is it's simplicity and elegance. e=mc2, for example.
I like to apply the medieval master's razor to manufactured and processed food products. Operating under the theory that most food additives are applied for the convenience of the manufacturer and retailer, the food version of Occam's razor is simply this: Choose the product with the shortest list of ingredients. Anything more is foolishness and vanity. First rate French or Italian bread contains only flours, water, salt, and yeast. The best ice cream consists of milk, cream, sugar, and a natural flavor.
Classic preserves contain only fruit and sugar. Apart from home made and an emerging cottage industry in small batch preserves, the best preserves I have found are the Swiss made Hero brand. They contain only fruit and sugar. Almost all domestic preserves and a good many imported ones have more than two ingredients. The addition of various corn syrups in place of sugar is a serious defect. The addition of pectin is usually a sign that the product is going to be very sweet. Any preserve or jam that says "all natural" or "all fruit" is probably an apple or grape juice concoction. The fruit juice is boiled down to a gummy sweetness that drowns out the flavor of the fruit pictured on the label. These products command premium prices. Many are imports and sit right next to the far superior Hero brand. The all fruit products have poor texture and muddied flavors, but they sell because the label can say "no sugar added". In preserves that is not a good thing.
Even so prosaic a food as peanut butter is not safe from the food complicators. Real peanut butter contains only peanuts. Salt is optional. While I was growing up it was discovered that the sliced bread like substance being marketed as a health food for the millions was too soft to stand up under the texture of peanut butter. What to do? Firm up the bread? Toast it? Stir the peanut butter? Nope, the solution was to process peanut butter by hydrogenation to enhance it with what we now know as trans-fatty acids, the greatest arterial clogger known to mankind. Then it was super whipped to remove all texture. To make it softer they added vegetable oil, creating a higher fat food. To make sure kids liked it, they added sugar. The result was Peter Pan, Skippy, Jif, and their imitators. Tasters, even professionals, are so removed from the root product that peanut butter once was, that the real thing seldom does well in comparative tests. Are we comparing apples and oranges, or was peanut butter a lousy food until the chemists added the extra fat and sugar and the trans-fatty acids?
Food processing has become the art of doing less with more.