Isolation and characterization of nettle (Urtica dioica L.) seed proteins: Conversion of underutilized by-products of the edible oil industry into food emulsifiers.

This study aimed to upcycle a byproduct of the edible oil industry, cold-pressed nettle seed meal (CPNSM), into a plant-based emulsifier, thereby increasing the sustainability of the food system. The protein content of the nettle seed protein (NSP) powder was 48.3% with glutamic acid (16.6%), asparagine (10.7%), and arginine (9.7%) being the major amino acids. NSPs had a denaturation temperature of 66.6 °C and an isoelectric point of pH 4.3. They could be used as emulsifiers to form highly viscous coarse corn oil-in-water emulsions (10% oil, 4% NSP). Nevertheless, 10-fold diluted emulsions exhibited rapid creaming under different pH (2-9), salt (0-500 mM NaCl) and temperature (>40 °C) conditions, but they were relatively stable to aggregation. Our findings suggest that NSPs could be used as emulsifiers in highly viscous or gelled foods, like dressings, sauces, egg, cheese, or meat analogs.

Acute and 28-day repeated dose toxicity evaluations of cold pressed Pinus halepensis Mill. seed oil in mice and rats.

Pinus halepensis Mill. seed (Pinaceae), popularly known as 'Zgougou', is widely consumed in the Mediterranean countries and used traditionally in the treatment of some diseases such as bronchitis, rheumatism, infection, and inflammation. The present study aimed to evaluate the oral safety of cold pressed oil of Pinus halepensis Mill. seeds (COPHS) by acute and 28-day repeated dose toxicities studies in Wistar mice and rats, respectively. In the acute toxicity study, oral administration of COPHS to mice did not provoke mortality or any toxic signs at doses up to 5000 mg/kg bw. After administration of COPHS at doses of 250, 500, and 1000 mg/kg bw/day for 28 days, no abnormal changes were observed in body weight, water intake, food consumption, organ weight, blood haematological, serum biochemistry parameters, and histology profile. Furthermore, there was no animal death or any symptom of toxicity in any group during sub-acute toxicity test period. Our findings demonstrate that COPHS is relatively non-toxic and has a large safety margin (>5000 mg/kg). The results of the present research provide basic reference data for food consumption and for future in vivo screening of biological and pharmacological properties of cold pressed oil of Pinus halepensis Mill. seeds.