PROBLEM TO BE SOLVED: To provide foods, feeds, or cosmetics having taste improving action, serum lipid improving action, increasing-inhibitory action of lipoperoxide, proliferation-promoting action of enteric useful bacteria, anti-caries action, or adjuvanticity.SOLUTION: A mannooligosaccharide-containing substance comprises suspending a coffee extraction residue in the solution comprising a volatile acid to prepare a suspension containing the coffee extraction residue at 1.0-40.0% (w/w)； heating the prepared suspension for 2 to 20 minutes at 150-190°C； and removing the residue from the suspension after heating to obtain a solution. In the method for producing the mannooligosaccharide-containing substance, a volatile acid is acetic acid or formic acid, the concentration of acetic acid in the solution is 0.1-10.0% (v/v), the concentration of formic acid is 0.05-1.0% (v/v), the yield of mannooligosaccharide is 20 mg or more per 1.0 g of the coffee extraction residue, and the furfural content in the mannooligosaccharide-containing substance is 3.0% (w/w) or less.【課題】呈味改善作用、血清脂質改善作用、過酸化脂質上昇抑制作用、腸内有用菌増殖促進作用、抗う蝕作用、又は免疫賦活作用を有する、食品、飼料或いは化粧品の提供。【解決手段】コーヒー抽出残渣を揮発性の酸を含む溶液に懸濁し、コーヒー抽出残渣を１．０～４０．０％（ｗ／ｗ）で含む懸濁液を調製する工程、調製した懸濁液を１５０～１９０℃で２～２０分間加熱する工程、及び加熱後の懸濁液から残渣を除去して水溶液を得る工程を含むマンノオリゴ糖含有物。揮発性の酸は、酢酸又はギ酸であり、溶液中の酢酸の濃度は、０．１～１０．０％（ｖ／ｖ）であり、ギ酸の濃度は、０．０５～１．０％（ｖ／ｖ）であり、マンノオリゴ糖の収量が、コーヒー抽出残渣１．０ｇあたり２０ｍｇ以上であり、マンノオリゴ糖含有物中のフルフラール含量が、３．０％（ｗ／ｗ）以下であるマンノオリゴ糖含有物の製造方法。【選択図】なし
