Background: The olive stone, a primary by-product of olive oil extraction, is mainly composed of a lignified shell and inner seed. It represents a substantial portion of the olive industry's biomass waste, contributing over 40 Mt annually. While typically regarded as waste, olive stones contain a variety of nutrients and bioactive compounds like lipids, proteins, phenolic compounds, and minerals found in the seed, as well as fibers in the shell. These elements hold significant value across multiple sectors, including food, energy, and agriculture. These phenolic compounds and nutrients provide notable antioxidant, anti-inflammatory, chemopreventive, and antimicrobial effects, supporting health and disease prevention. Scope and approach: This review explores the sustainable utilization of olive stone by-products, highlighting their potential to contribute to human health and environmental sustainability. It discusses the practical applications of olive stones in various domains, from functional ingredients in food products and pharmaceuticals to renewable energy sources and soil-enhancing agricultural inputs. Key findings and conclusions: Olive stones, particularly olive seeds, are rich in dietary fiber (47.6 %), lipids (30.4 %), proteins (13.5 %), and phenolic compounds (8.10 %), especially n & uuml;zhenide, n & uuml;zhenide 11-methyl oleoside and methoxyn & uuml;zhenide, and demonstrate a range of health-promoting properties. Additionally, they are shown to benefit metabolic health by combating disorders such as diabetes, hyperlipidemia, obesity, and car- diovascular and neurodegenerative diseases while also protecting organ functions like those of the liver and kidneys. The review underscores the promise of olive stone by-products as a sustainable, health-benefiting resource in circular economy practices within the olive oil industry.

The extensive use of non-biodegradable and petroleum derived polymers in industry exacerbates environmental problems associated with plastic waste accumulation and fossil resource depletion. The most promising solution to overcome this issue is the replacement of these polymers with biodegradable and bio-based polymers. In this paper, novel biocomposites were prepared from bio-based polyamide 5.6 (PA56) with the addition of olive stone powder (OSP) at varying weight concentrations by melt compounding method. The degradability of the prepared biocomposites is investigated through soil burial test, and assessed by reduction in their mechanical properties. The biodegradability of bio-based polyamide 5.6 is shown to be improved by addition of olive stone powder, and its effects on the properties of polymer matrix are elucidated. The Fourier transform infrared (FTIR) spectrum of the biocomposites indicate the successful incorporation of OSP into PA56 polymer matrix. After six-month soil burial test, scanning electron microscopy and FTIR show the degradation of PA56 through morphological and structural changes, respectively. Differential scanning calorimetry reveals the changes in the transition temperatures of the polymer matrix and an increase in crystallinity. Thermogravimetric analysis is used on the biocomposite to determine the fraction of its components, polymer and biofiller, and the results show that 2.67% (w/w) of the polyamide 5.6 is biodegraded at the end of the six-month soil burial.