Novel and Facile Colorimetric Detection of Reducing Sugars in Foods via In Situ Formed Gelatin-Capped Silver Nanoparticles

An easy-to-use platform for colorimetric determination of dextran: A potential application for the sugar industry

A user-friendly platform based on foam sheets and silica solid support was developed for colorimetric sensing of dextran via phenol-sulfuric acid assay. The chemical reagents, sulfuric acid and phenol were separately preserved by silica gel. The brown color product of the phenol-sulfuric acid reaction occurred on the silica solid support when sample solutions were added. The color intensity of brown products was easily obtained by a smartphone and color processing software. Subsequently, a broad concentration range of dextran could be determined up to 10,000 mg/L dextran, with a detection limit of 360 mg/L. Furthermore, a precision study, including inter-day and intra-day studies, presented a satisfactory performance for dextran detection. The developed platform was successfully applied for the sugar industry's dextran determination of syrup samples.

Bioactive Compounds and Sensory Quality in Chips of Native Potato Clones (Solanum tuberosum spp. andigena) Grown in the High Andean Region of PERU

Native potatoes (Solanum tuberosum spp. andigena) have diverse pigments and are cultivated in Peru's high Andean regions; they are characterized by containing bioactive compounds that prevent various degenerative diseases. The study aimed to evaluate the physicochemical and sensory quality in chips of native potato clones grown at 3496 m altitude, for which the potatoes were cut into slices and fried in extra virgin olive oil at 180 °C for 200 s. This was determined by proximal analysis, reducing sugars, minerals, color, antioxidant capacity (AC), total phenolic compounds (TPC), and anthocyanins in fresh and chips; an instrumental characterization by FTIR and SEM and sensory tests were also performed. The native potatoes presented low moisture and reduced sugar contents; when frying, their bioactive properties improved, increasing AC, TPC, and trace elements, such as K, Mg, Ca, P, Fe, and Zn. To conclude, fresh clones have high yields in the field and are an essential source of nutrients and bioactive; the salt-free chips of clone B presented better physicochemical properties and greater sensory acceptance, closely followed by clone A. Both clones could be used as raw material by food companies that produce snacks to benefit high Andean agricultural producers.