No abstract

Grape seeds are one of the most accessible by-products of the wine industry in large quantities (about 2.4 million t/year). Numerous researchers have shown that grape seeds have a high potential for use as a functional ingredient in the food industry due to their high content of protein, fiber, minerals, and polyphenols. The aim of the paper is to evaluate the possibilities of using grape seed flour (GSF) in the bakery industry from both chemical and rheological points of view. Research shows that grape seed flour contains about 42 times more fiber than wheat flour and approximately 9 times more calcium, 8 times more magnesium, and 2 times more potassium. To assess this potential, four samples of bread from flour mixtures with 3%, 5%, 7%, and 9% (w/w) degree of replacement with GSF were prepared, analyzed, and compared with a control sample from 100% wheat flour. From a rheological point of view, the baking qualities deteriorate: the water absorption capacity (CH) decreases from 58.2% to 55.8%, the dough stability increases from 8.50 min to 9.83 min, the α slope varies from −0.066 Nm/min to −0.104 Nm/min, the β slope increases from 0.576 Nm/min to 0.630 Nm/min, and the γ slope varies from −0.100 Nm/min to −0.198 Nm/min. The sensory analyses performed by the panel of evaluators enclosed the sensorial characteristics of the samples with 3% and 5% GSF between the two control samples made from flour types 480 and 1250. The conclusions show that the sample containing 7% and 9% are unsatisfactory from rheological and sensorial points of view and the samples with 3% and 5% can be considered a fiber source and a Cu source, respectively, and are rich in Zn.

Pumpkin (Cucurbita maxima) seeds are a rich source of ingredients such as aminoacids, fatty acids, minerals, and phytochemicals exhibiting nutraceutical effects on human health. In this work, partially defatted pumpkin seeds flour, a by-product obtained during the manufacture of pumpkin seeds oil, was studied as an additive for common wheat flour. We explored the physico-chemical properties as well the content in amino acids of the partially defatted pumpkin seeds. The obtained results revealed that partially defatted pumpkin seeds are a good source of protein (42.75% d.m.), lipids (12.28% d.m.), total carbohydrates (37.4% d.m.), from which crude fiber (26.64% d.m.). This by-product presents a high mineral content (mg/100g): potassium (1290), magnesium (693), iron (87.8), zinc (11.5) and copper (2.49).The partially defatted pumpkin seeds proteins contain significant amounts of essential amino acids such as valine, histidine, isoleucine, leucine, threonine and methionine.

Grape skin is considered a valuable by-product for antioxidant and antibacterial agent preparation. The grape skin contains some active compounds, such as, dietary fiber, polyphenols, flavonols, and resveratrol; it is commonly used as a nutritional supplement. The main aim of this study was to establish the optimum dose of grape skin flour, to be used as a functional ingredient in the bakery products industry, from both chemical and rheological point of view. The laboratory experiments evaluated the functional potential of wheat flour enriched with grape skin flour, in different proportions, by examining the chemical composition and rheological behaviour of the doughs. Protein, crude fibre, fat, ash and mineral contents were determined. Using �H-NMR spectral technique, the fatty acids composition was determined, especially the concentrations of short-chain saturated fatty acids (C4-C8), di-unsaturated fatty acids, mono-unsaturated fatty acids and long-chain saturated fatty acids (]C8). 1H-NMR spectra were recorded on a Bruker Ascend 400 MHz spectrometer. The rheological behaviour was analyzed using the predefined Chopin + protocol on Mixolab, an equipment of CHOPIN Technologies. Grape skin flour was incorporated into wheat flour at three different levels, 5, 10 and 15% and it was found that incorporation up to a 15% level into the formulation of wheat flour yielded an acceptable product in terms of rheological parameters, with improved chemical, nutritional and functional properties.

Taking into consideration the circular economy context, from cereal production and processing result by-products and residues which can be transformed into the new raw materials. Straw, husks, brans, flours, bread waste, confectionary waste, so on, can be re-used using different processes such as: extraction, fermentation, microorganism cultivation, for obtaining added value products. These new products obtained can be: biofuels, enzymes, biodegradable material food contact, single cell protein, bio-adsorbent, nanoparticles, bio alcohol, bioactive compounds like fibres, phytochemicals, minerals, so on. This paper is a short review regarding sharing knowledge and good practices in implementing circular economy within food systems, specifically, cereal supply chain.