Color and Bioactive Compounds Characteristics on Dehydrated Sweet Cherry Products

Abstract

It is widely known that quality properties of fruits can be affected by drying processes. The approach was the quality improvement of dried cherry products through the application of combined technologies of drying and pretreatments. The objective of this work was to analyze the effect of blanching or sugar infusion prior to air-drying or freezedrying on quality properties such as color, bioactive compounds, and antiradical power of two cherry products (discs and dices). Air-drying caused darkening, whereas freezedrying provoked higher lightness of discs compared to fresh fruit (p<0.05). Cherry dices were lighter than the fresh fruit. A high retention of total anthocyanin (ACY) and phenolic content (TPC) was obtained in blanched freeze-dried discs (ACY = 165 ± 22 mg Cyd-3-glu/100 g d.w.; TPC = 739 ± 55 mg GAE/100 g d.w.). Sugar infusion pretreatment caused an important decrease in ACY (31-89 mg Cyd-3-glu/100 g d.w.) and TPC (222-271 mg GAE/100 g d.w.). When blanching was applied prior to air-drying, samples presented the highest antiradical power, similar to that observed in fresh fruit. In dices, the best quality attributes in terms of superficial color were found in control freeze-dried samples since they presented minor shifts in hue angle and a greater preservation of anthocyanin pigments (ACY=211 ±30 mg Cyd-3-glu/ 100 g d.w.). However, control air-dried dices presented the highest phenolic content (TPC=771±65 mg GAE/100 g d.w.). Regarding the possible application of the dry cherry products, discs could be directly consumed as snacks, while dices could be incorporated as ingredients in fruit bars, cookies, or muffins.

Valorization of postharvest sweet cherry discard for the development of dehydrated fruit ingredients: compositional, physical, and mechanical properties

“…The migration of water‐soluble substances contained in the vacuoles towards the surrounding medium therefore takes place because the syrup formed during the SI consists in a hypertonic solution composed mainly by sucrose, which is diluted throughout time as a result of the sugar intake and the water loss exhibited by the fruits. This phenomenon was previously reported for sweet cherry pieces, various berries, and other fruits . It is interesting to note that despite the decrease in bioactive compounds (phenolic and anthocyanin) from IS pretreatment, the phenolic contribution to the antioxidant capacity of the ingredients is still considerable.…”

“…Sweet cherry ingredients were placed on two petri dishes and measurements were done on eight different points of each dish ( n = 16). The L*a*b* parameters were used to calculate the following color functions: ‘chroma’ (C* ab ), ‘hue angle’ (h ab ) and ‘global color change’ (ΔE* ab ) …”

“…Dry sugar infusion (SI) pretreatment was carried out by immersing the fruits at 25 ∘ C into a dry mixture of sucrose and preservatives. The amount of sucrose was calculated for 1 kg fruit to reduce a w to 0.87 using the method described in Franceschinis et al 12 The fruit/sugar ratio was 0.7 and potassium sorbate (100 mg/kg of food system) and sodium bisulfite (150 mg/kg of food system) were used as antimicrobial and anti-browning agents. The fruits and the syrup generated during the treatment were carefully mixed twice a day until the equilibration of food system components was reached after 15 days.…”

“…Total sugar content (TS), total phenolic compound content (TPC) and monomeric anthocyanin content (ACY) were determined on ethanolic extracts (80%) using the method described in Franceschinis et al 12 An anthrone/sulfuric acid procedure and glucose (GLU) as standard were used for TS. Folin-Ciocalteu reagent was used to estimate TPC, and gallic acid (GA) was employed as standard.…”

Fruit snacks from raspberries: influence of drying parameters on colour degradation and bioactive potential

“…Although conventional hot air‐drying is one of the most economical drying techniques, water loss and heating usually cause stresses in the cellular structure, leading to changes in shape and volume decrease because of cell and intercellular spaces collapse (Michailidis & Krokida, ). It is also known that drying at high temperatures and long times may affect flavour, colour and nutrients of dried food (Franceschinis et al ., ). In contrast, during freeze‐drying, the solid state of water and the low temperatures protect the primary structure and the shape of the products with minimal volume reduction.…”