The present research aimed to evaluate the use of spent coffee grounds (SCG) from instant coffee as a food ingredient and its application in bakery products. Data on physicochemical characterization, thermal stability and food safety of SCG were acquired. Evaluation of feasibility as dietary fibre was also determined. Results showed SCG are natural source of antioxidant insoluble fibre, essential amino acids, low glycaemic sugars, resistant to thermal food processing and digestion process, and totally safe. In the present work, SCG were incorporated in biscuit formulations for the first time. Low-calorie sweeteners and oligofructose were also included in the food formulations. Nutritional quality, chemical (acrylamide, hydroxymethylfurfural and advanced glycation end products) and microbiological safety and sensory tests of the biscuits were carried out. Innovative biscuits were obtained according to consumers' preferences with high nutritional and sensorial quality and potential to reduce the risk of chronic diseases such as obesity and diabetes.
The aim of this study was to evaluate the inhibitory potential of aqueous extracts from coffee silverskin (CSE) and husk (CHE) and their main phenolics on adipogenesis, obesity-related inflammation, mitochondrial dysfunction, and insulin resistance, in vitro. Coffee by-products extracts (31-500 μg mL-1) and pure phenolics (100 μmol L-1) reduced lipid accumulation and increased mitochondrial activity in 3T3-L1 adipocytes. Also reduced the expression of inducible nitric oxide synthase and cyclooxygenase-2 and diminished secretion of pro-inflammatory factors in LPS-stimulated RAW2643.7 macrophages. Cytokine release diminished (tumor necrosis factor α: 23-57%; monocyte chemoattractant protein 1: 42-60%; interleukin-6: 30-39%) and adiponectin increased (7-13- fold) in adipocytes treated with macrophage-conditioned media. ROS scavenging and activation of peroxisome proliferator-activated receptor γ coactivator 1-α pathway counteracted mitochondrial dysfunction. Increases in insulin receptor (1.4 to 4-fold), phosphoinositide 3-kinase (2 to 3-fold) and protein kinase B (1.3 to 3-fold) phosphorylation, in conjunction with a decrease in serine phosphorylation of insulin receptor substrate 1, evoked glucose transporter 4 translocation (8-15-fold) and glucose uptake (44-85%). CSE and CHE phenolics inhibited adipogenesis and elicited adipocytes browning. Suppressing macrophages-adipocytes interaction alleviated inflammation-triggered mitochondrial dysfunction and insulin resistance. CSE and CHE are beneficial in reducing adipogenesis and inflammation-related disorders.