Apple pomace is the solid residue left over after apples are pressed for juice or cider. It consists of the crushed skin, flesh, seeds, and stems, with skin and flesh making up about 95% of the material and seeds and stems accounting for the rest. Roughly 25% to 30% of every apple processed becomes pomace, and globally that adds up to around 4 million tons per year.
How Apple Pomace Is Produced
Any facility that presses apples generates pomace. Juice factories, cider houses, and producers of dried or frozen apple products all create it in large quantities. China, the world’s largest apple producer, generates over one million tons of pomace annually. Poland produces roughly half a million tons per year, and Germany about 250,000 tons. As global apple production tops 87 million tons per year, pomace volumes are expected to keep rising.
Fresh pomace is wet, heavy, and spoils quickly. It can be dried into a shelf-stable powder for food or supplement use, fed directly to livestock, composted, or processed further to extract valuable compounds like pectin and polyphenols.
Nutritional Composition
On a dry weight basis, apple pomace is mostly carbohydrates (45% to 84%), including simple sugars like fructose and glucose. Its standout nutritional feature is dietary fiber, which ranges from about 15% to 65% of dry weight depending on the apple variety and how thoroughly the juice was extracted. The majority of that fiber is insoluble: cellulose makes up roughly 43%, with hemicellulose adding another 20% to 32%. These insoluble fibers are the types that support digestive regularity by adding bulk.
Protein content is low, typically 1% to 5% of dry weight in the pomace as a whole. The seeds, however, are notably richer, containing around 49% protein and 24% fat. Because seeds are a small fraction of total pomace, they don’t dramatically shift the overall nutritional profile, but they do contribute some lipids, including unsaturated fatty acids and vitamin E compounds.
Polyphenols and Antioxidant Activity
Much of the interest in apple pomace comes from its polyphenol content. These are plant compounds with antioxidant properties, meaning they help neutralize the unstable molecules that can damage cells. Apple pomace is particularly rich in chlorogenic acid (a phenolic acid), catechins and epicatechins (flavonoids), and a compound called phloridzin that is relatively unique to apples.
Quercetin, a well-studied antioxidant found in apple skins, shows up in several forms in pomace. Lab analyses have measured quercetin-3-O-galactoside at about 22.5 mg per 100 grams of dry pomace, with quercetin-3-O-rhamnoside close behind at 19.2 mg. Total phenolic content in one analysis came to 89.4 mg per 100 grams of dry material, with total flavonoid content at 94.3 mg per 100 grams. In cell studies, catechin and epicatechin from apple pomace have shown the ability to inhibit the oxidation of LDL cholesterol, which is one of the early steps in arterial plaque formation.
Pectin Extraction
Pectin is a soluble fiber widely used as a gelling agent in jams, jellies, and other foods, and apple pomace is one of the commercial world’s primary sources of it. Extraction yields typically range from about 15% to 23% of pomace dry weight, depending on the method used. Conventional acid-based extraction with citric or hydrochloric acid pulls out 14% to 19%, while newer techniques like microwave-assisted extraction can push yields above 23%.
This makes pectin recovery one of the most economically viable uses of apple pomace. Rather than treating the material as waste, processors can extract pectin and sell it to the food industry, where demand is steady and growing.
Use in Food Products
Dried and ground into a fine powder, apple pomace can be added to baked goods, snack bars, pasta, and other foods as a fiber and antioxidant booster. Its mild, slightly sweet flavor makes it easier to incorporate than many other plant byproducts. Researchers have tested it in gluten-free breads, where it improved both the nutritional profile and the antioxidant activity of the finished product.
Beyond fiber and polyphenols, pomace contributes malic acid (which adds tartness), natural sugars, and yellow-orange pigments that can enhance the color of food products without artificial dyes. The seed oil fraction, rich in unsaturated fatty acids, has also attracted interest as a specialty ingredient.
Use in Animal Feed
Apple pomace has a long history as livestock feed, particularly for cattle. Its energy content is lower than corn silage, roughly comparable to average-quality hay, so it works best as a supplement rather than a primary feed. Michigan State University Extension recommends keeping apple pomace below 20% of a cattle diet as a precaution, though 40 to 60 pounds of wet pomace per day is a common range for beef cows.
It fits best in the diets of animals with lower energy demands, such as cows in the second trimester of pregnancy. Its protein content is too low to serve as a protein source, so it needs to be paired with higher-protein feeds. The high moisture content of fresh pomace also means it must be fed quickly or ensiled to prevent spoilage.
Biogas and Energy Recovery
Because apple pomace is rich in organic matter, it can be broken down through anaerobic digestion to produce methane for energy. Research has shown that blending pomace at up to 15% with animal manure produces methane yields comparable to manure alone, around 380 to 420 milliliters of methane per gram of organic material per day. Pushing the pomace fraction to 30%, however, significantly reduced methane output, likely because the acidity of the pomace disrupted the microbial communities doing the digestion.
For farms and food processors looking to reduce waste while generating renewable energy, co-digesting moderate amounts of apple pomace with manure is a practical option that avoids the need for landfill disposal.
Safety Considerations
Apple seeds contain amygdalin, a compound that releases small amounts of cyanide when broken down by digestive enzymes. In whole apples, this is a negligible concern because people rarely chew and swallow enough seeds to matter. In pomace, the seeds are crushed during pressing, which could make the amygdalin more accessible. Swallowing the occasional seed is not a problem, but concentrated seed consumption, particularly by children, carries real risk including stomach pain and illness.
For commercial food products made with apple pomace, manufacturers typically account for seed content during processing. If you’re using pomace powder at home, choosing products from established suppliers helps ensure the material has been processed with seed content in mind.