Abstract
In this study, a new starch has been isolated from acorn (Quercus ilex) fruits. The chemical composition of acorn flour showed its richness in carbohydrates (64.43%), proteins (8%), and fat (10%). The extraction yield of acorn starch was about 34.5%. Thus, the composition of extracted acorn starch and its physical and functional properties were studied. Acorn starch had high purity represented by low proportions of proteins (0.92%) and lipids (0.51%) with a pH of 5.3. The swelling power was 20.76 g/g, while the solubility was about 64.22% at 90°C which suggests that acorn starch has potential for use in food industries. The FT-IR spectra of isolated native starches have shown the main bands characterizing the starch. However, X-ray diffractograms exhibited an A- and B-type diffraction pattern. Furthermore, the effect of acorn starch incorporation at different levels (0.5%, 1%, 1.5%, and 2%) on the quality parameters of a fermented dairy product was investigated at the beginning of storage. The results demonstrated that the most suitable dose of acorn starch to be incorporated in the fermented dairy product was lower than 1%. This low concentration reduced syneresis, improved functional properties, and enhanced the viscosity of the fermented dairy product.
Highlights
Genus Quercus acorns belong to the family Fagaceae, which includes several species such as Quercus robur, Quercus petraea, Quercus ilex, and Quercus pubescens [1]
Three batches of pasteurized milk were prepared and each batch was incorporated with one concentration of acorn starch (0%, 1%, and 2%) and inoculated with a freeze-dried starter culture, consisting of a combination of Streptococcus salivarius subs. thermophilus and Lactobacillus delbrueckii subs. bulgaricus
Carbohydrates, protein, ash, and moisture contents of acorn flour were 64.43%, 8%, 1.62%, and 15.95%, respectively. ese results were partially in accordance with those reported by Charef et al [23] and Masmoudi et al [24]
Summary
Genus Quercus acorns belong to the family Fagaceae, which includes several species such as Quercus robur, Quercus petraea, Quercus ilex, and Quercus pubescens [1]. Being mainly a source of carbohydrates, fats, and fibers, acorn kernels are nutritionally comparable to many cereal grains These kernels contain proteins, high content of essential amino acids, vitamins (mostly A and C), and minerals. Since acorns have always been an attractive food resource in human diet and are good sources of starch, these fruits show a large potential for commercial use, and acorn flour may be an interesting component [4]. There is no scientific research dealing with the effect of modified starch substitution by extracted acorn starch in dairy fermented products In this regard, in the present study, we evaluated the effect of acorn starch incorporation in milk in order to improve the physicochemical, organoleptic, and rheological quality as well as syneresis variation of a new produced fermented product after manufacture
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
