Development of grape pomace meal replacement powder

【Objective】To develop functional meal replacement foods using grape pomace， which could provide a new way for the high-value utilization of grape processing by-products.【Method】In this study， using different addition ratios （2%， 3%， 4%， 5%， 6%） based on the base ingredient formulation， both common crushed grape pomace （CCGP） and ultrafine grinding grape pomace （UGGP） were compounded with buckwheat flour， pea flour， and konjac flour to create meal replacement powder. The study compared the effects of the two types of grape pomace on the qualities of meal replacement powders such as brew ability， powder properties， active ingredients， and antioxidant activity， the best formulation was also obtained by screening the sensory scores as an indicator， and the nutrient component content and glycemic index （GI） of the best formulated products were further analyzed.【Result】The experimental results showed that both types of grape pomace could improve the brew ability， powder properties， total phenolic content， antioxidant activity， and rheological properties of meal replacement powders. Among them， compared to the meal replacement powder without grape pomace added， the meal replacement powder with 5% UGGP added exhibited superior dispersibility and expansibility of 4.14% and 45.78% respectively， meal replacement powder adding 2% UGGP increased bulk density by 18.46%， while meal replacement powder adding 3% UGGP reduced caking rate by 22.73%. Scanning electron microscopy results indicated that ultrafine grinding could greatly reduce the particle size of grape pomace to 5-10 μm. Furthermore， the meal replacement powder with 6% UGGP added had a higher total phenolic content and stronger antioxidant activity， reaching 16.71 mg/g total phenolic content， showing an increase of 61.76% compared to the meal replacement powder without grape pomace added. Its scavenging capacity of 1,1-diphenyl-2-picrylhydrazyl （DPPH） radical， scavenging capacity of diammonium 2,2-azino-bis（3-ethylbenzothiazoline-6-sulfonate） （ABTS） cation radical， and hydroxyl radical， as well as iron ion reducing capacity increased by 45.85%， 22.04%， 107.23%， and 81.52% respectively， compared to the meal replacement powder without grape pomace added. Sensory analysis results indicated that adding 5% UGGP was the optimal formulation for meal replacement powder. Under this condition， the product had crude protein content of 15.15 g/100 g， soluble carbohydrate content of 30.17 g/100 g， total dietary fiber content of 20.80 g/100 g， and crude fat content of 1.47%； the GI value was 40.09.【Conclusion】The addition of UGGP can greatly improve the brew ability， powder properties， sensory quality， rheological properties， and antioxidant activity of meal replacement powder， with an optimal addition level of 5%. The final product appears light purple， retaining some grape flavor， and has a delicate texture after preparation， without acidity or astringency. It features high protein， high dietary fiber， and low fat， classifying it as a high-nutrition， low-GI food with potential to be applied as a diabetes-friendly functional food.