Coffee silverskin, a by-product of the coffee roasting industry, offers significant potential for valorization due to its bioactive compound content. This study optimized the Pressurized Liquid Extraction (PLE) process for recovering phenolic compounds and caffeine from coffee silverskin. A factorial design identified the temperature and ethanol concentration as the key parameters influencing extraction yield, antioxidant capacity (TEAC), total phenolic content (TPC) and caffeine and phenolic acid contents. These factors were further optimized using a central composite design (CCD) and Response Surface Methodology (RSM). The optimal extraction conditions—140 °C and 55% ethanol—achieved a balanced enhancement across all responses: 12.1% extraction yield, 65.3 mg TE/g dry extract for antioxidant capacity, 88.4 mg GAE/g dry extract for total phenolic content, 56.7 mg caffeine/g dry extract, and 10.6 mg chlorogenic acid equivalents/g dry extract for phenolic acid content. Compared to conventional methods, the optimized PLE demonstrated superior bioactive compound recovery while employing environmentally friendly solvents. This approach underscores PLE’s potential as a sustainable technology for valorizing agro-industrial by-products, contributing to both waste reduction and the development of antioxidant-rich products.

Sunflower press cake (SPC), a by-product of the edible oil industry, represents a promising source of plant-based protein. This study aimed to investigate and optimize protein recovery from SPC using conventional (CE) and advanced extraction techniques, including Ultrasound and Microwave-Assisted Extraction (UMAE), Pressurized Liquid Extraction (PLE) and Enzyme-Assisted Extraction (EAE). The protein content both in extracts and in the precipitated mass was measured through Lowry assay, while the amino acid profile of the extracted proteins under optimal conditions was analyzed via High-Performance Liquid Chromatography (HPLC). Extraction parameters were optimized using response surface methodology (RSM) for each method. Among the novel methods studied, UMAE and PLE demonstrated superior efficiency over CE, yielding higher protein recovery in significantly shorter extraction times. Optimal UMAE conditions (10 min, 0.03 g/mL, 450 W microwave power, and 500 W ultrasound power) yielded a precipitation yield (PY) of 21.2%, protein recovery in extract (PR_E) of 79.9%, and protein recovery in precipitated mass (PR_P) of 66.3%, with a protein content (PC_P) of 902.60 mg albumin eq./g. Similarly, optimal PLE conditions (6 min, 0.03 g/mL, and 50 °C) resulted in PY, PR_E, and PR_P of 17.7, 68.9, and 47.4%, respectively, with a PC_P of 932.45 mg albumin eq./g. EAE using Aspergillus saitoi protease was comparatively less effective. The amino acid profiling confirmed SPC as a valuable protein source, with glutamic acid, arginine, and aspartic acid being the most abundant. These results highlight the potential of UMAE and PLE as efficient strategies for valorizing edible oil industry by-products into high-quality protein ingredients for food and biotechnological applications.

Berries are highly perishable due to their high water content, making them prone to rapid deterioration and spoilage. This study investigates the effects of osmotic dehydration and edible coatings, with and without bioactive compounds, on various quality attributes of blueberries, raspberries, and strawberries during storage. The berries were pretreated using osmotic dehydration with apple juice, followed by the application of edible coatings from Chlorella vulgaris protein, with or without the addition of aqueous rosemary extract as a source of bioactive compounds. The results indicated that the combination of the two methods significantly reduced weight loss in all berry types, with the incorporation of bioactive compounds further enhancing moisture retention up to approximately 3% for blueberries and raspberries and 5% for strawberries. Total phenolic content and antioxidant activity exhibited significantly increased stability in coated samples, with bioactive coatings contributing to improved antioxidant properties. The HPLC analysis proved that the bioactive profile was preserved after the treatments. Microbial analysis demonstrated that edible coatings, particularly those enriched with bioactive compounds, effectively inhibited microbial growth (TC approximately 4.5 log(CFU/g) with limit = 5 log(CFU/g) and YM approximately 3.5 log(CFU/g) with limit 4 log(CFU/g)), thereby extending the shelf life of the berries. These findings suggest that the synergistic application of osmotic dehydration and edible coatings, especially those containing bioactive compounds, significantly enhances the quality, shelf life, and potential health benefits of fresh berries during storage.

Fresh-cut potatoes are highly perishable, requiring effective preservation strategies to maintain quality and extend shelf life. This study evaluated the use of edible coatings and the combination of osmotic dehydration and ohmic heating (OH-OD), both integrated with modified atmosphere packaging (MAP), to enhance microbial stability and reduce quality deterioration. Key quality parameters—including color stability, browning index, weight loss, microbial activity, and sensory attributes—were assessed. Results showed that coated samples (E-FP) had the lowest browning index (59.71) by day 8, compared to a value of 62.69 in control samples (C-FP). OH-OD-treated samples exhibited the least weight loss (6.73%) versus 17.75% in C-FP. Microbial analysis showed that E-FP samples maintained the lowest total viable count by day 8 (3.98 ± 0.02 log CFU/g), compared to OH-OD-FP (4.43 ± 0.13 log CFU/g) and C-FP (4.79 ± 0.06 log CFU/g), confirming the antimicrobial efficacy of the edible coating enriched with rosemary essential oil and ascorbic acid. Sensory evaluation further confirmed that coated samples retained superior sensory qualities, receiving the highest overall acceptance score of 8.86 ± 0.80, compared to values of 7.80 ± 0.98 for control samples (C-FP) and 2.80 ± 0.69 for OH-OD-FP samples, highlighting their enhanced consumer appeal. These findings highlight that combining advanced preservation techniques with MAP can significantly reduce moisture loss and microbial spoilage while maintaining freshness and sensory appeal. This integrated approach offers a promising solution for extending shelf life, reducing food waste, and supporting sustainability in response to consumer demand for minimally processed, high-quality fresh products.

Rapeseed press cake (RPC), the protein-rich residue from edible oil production, is currently underutilized and is primarily used as animal feed. This study aimed to investigate pressurized liquid extraction (PLE) for protein recovery from RPC using response surface methodology (RSM) with precipitation yield (PY) as the response variable. Following alkaline extraction, proteins were precipitated at their isoelectric point, and solid residues were freeze-dried to obtain protein powders. Conventional extraction (CE) under magnetic stirring at room temperature was used as a reference. The results demonstrated that increasing pH from 8 to 11 significantly enhanced protein extraction efficiency for both methods. PLE exhibited superior performance, achieving higher PY compared to CE while drastically reducing extraction time from 120 min (CE) to 6 min (PLE). Optimal conditions were identified at a solid-to-liquid ratio of 0.10 g/mL, 150 °C, and 6 min, yielding a PY of 14.9%, protein recovery in extract (PR_E) of 43.8%, and protein recovery in precipitated mass (PR_P) of 20.0%, with a protein content (PC_P) of 647.2 mg albumin eq./g. RSM analysis identified extraction temperature as the most critical parameter for PLE, highlighting its dominant role in mass transfer. Finally, amino acid (AA) analysis revealed that protein powders were rich in essential AAs, with glutamic and aspartic acids being the most abundant. Additionally, PLE-derived protein powders exhibited enhanced solubility. This study confirms PLE as a highly promising and time-efficient technique for protein recovery from RPC, supporting the potential of sustainable valorization of agro-industrial by-products and promoting a circular economy model within the food industry.