The search for new natural sources of hydrocolloids with stabilizing, thickening, and good binding capacity, from raw materials that are environmentally friendly and that contribute to the circular economy is a challenge for the food industry. The aim of the study was the preliminary characterization of a spray-dried hydrocolloid from high Andean algae Nostoc sphaericum. Four ecotypes of algae from Peruvian high Andean lagoons located above 4000 m were considered. The samples were collected in the period March–April 2021 and were subjected to a spray drying process in an aqueous medium. The characterization showed that the dehydrated nostoc ecotypes presented high protein and carbohydrate content, making it a potential material for direct use as a functional food for humans. The spray-dried product presented good stability for its use as a hydrocolloid, with zeta potential values (ζ), around 30 mV, evidencing the presence of -CO-, -OH, -COO-, and -CH groups, characteristic of polysaccharides, representing 40% of total organic carbon on average, giving it low water activity values and particle size at the nanometric level. Major minerals such as Ca (>277 mg/100 g), Mg (>19.7 mg/100 g), and Fe (>7.7 mg/100 g) were reported. Spray-dried nostoc is a hydrocolloid material with high potential for the food industry, with good nutritional content and techno-functional behavior.

The water from the high Andean rivers is peculiar due to its composition and the geomorphology of its sources, and naturally or anthropogenically contamination is not discarded along its course. This water is used for agriculture and human consumption, therefore knowing its quality is important. This research aimed to proposing and formulate a water-quality index for high Andean basins through the Delphi method, and its application in the Chumbao River located in Andahuaylas-Peru. Forty-three water-quality parameters were evaluated through the Delphi method, and the water-quality index (WQI_HA) was formulated with a weighted average of the weights of the selected parameters, it was compared with the WQI Dinius. For this purpose, ten sampling points were considered along the Chumbao River located between 4274 and 2572 m of altitude and the WQI_HA was applied. In addition, field and laboratory analyses were carried out in 2018, 2019, and 2021, in dry and rainy seasons. Twenty parameters were grouped in the physicochemical sub-index (SI_PC), heavy metals sub-index (SI_HM), and organic matter sub-index (SI_OM). Each group contributed with weights of 0.30, 0.30, and 0.40, respectively, for the WQI_HA formulation. The SI_PC and SI_OM showed that the areas near the head of the basin presented excellent and good quality, while the urbanized areas were qualified as marginal to poor; SI_HM reported good quality in all points and seasons. Regarding the WQI_HA, the index shows good quality in the zones above 3184 m of altitude, contrasting with poor quality downstream, decreasing notably in both seasons, suggesting continuous degradation of the water body.