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

Abstract

Raspberries were dehydrated using air and freeze-drying with wet and dry sugar infusion pretreatments. Product quality factors such as colour, bioactive compounds, antioxidant capacity and sensorial characteristics were analysed. Special emphasis was placed on the analysis of anthocyanin degradation and its relationship with colour deterioration and with polymeric compounds development and browning. Freezedried raspberries presented a higher retention of bioactive compounds and a lower content of polymeric compounds than air-dried ones. Dried samples without pretreatment (control) showed the highest retention of total phenolic content (freeze-dried %82% and air-dried %37% retention), but the lowest sensory acceptability. Although sugar infusion pretreatments caused an important loss of bioactive compounds (9-18% of TPC retention), a higher sensorial acceptability was obtained. Pretreatments with bisulphite and acid allowed obtaining the best quality attributes in terms of anthocyanin and polyphenol content, antiradical activity and colour retention. Polyphenol intake through pretreated dried raspberries (115-299 mg gallic ac./100 g intake) would be higher in some cases than that of usually consumed foods as vegetables, cereals and several fresh fruits.Fruit snacks from raspberries P. Sette et al. 314 Fruit snacks from raspberries P. Sette et al.

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.…”

“…Monomeric anthocyanin content was quantified using the pH-differential method and expressed as cyanidin-3-glucoside (MW: 445.2 and a molar extinction coefficient = 29 600 L cm −1 mol −1 ) per kg of ingredient. The antioxidant capacity was determined according to Sette et al 13 by two different methods: antiradical power (ARP) by using the bleaching method of the radical 1,1-diphenyl-2-picrylhydrazyl (DPPH · ) and the ferric ion reducing ability (FRAP). Antiradical power was defined as the inverse of EC 50 and corresponds to the concentration that scavenged 50% of the radicals.…”

Influences of a natural colourant on colour and salty taste perception, liking, emotion and purchase intent: a case of mayonnaise‐based dipping sauces

“…Wadhera & Capaldi-Phillips (2014) stated that visual cues, such as colour, can affect sensory acceptance of a food by affecting expectation of palatability of such food, which can further influence food choice and consumption. Relationships between colour of foods and beverages and their physicochemical properties, overall quality and sensory acceptance have been reported in the literature (Canas et al, 2016;Hao et al, 2016;Kim et al, 2016;Sette et al, 2017). A number of studies have reported effects of colour on perception of tastes and their intensities (Johnson & Clydesdale, 1982;Chan & Kane-Martinelli, 1997;Hoegg & Alba, 2007;Wei et al, 2012).…”

Ranking and multicriteria decision making in optimization of raspberry convective drying processes

“…Sette and coworkers also reported that the value of redness (a*) increased after freeze‐drying. When considering this results, it was taken into account that after freeze‐drying, free water from raspberry is replaced by air, so the variations in red color and lightness can be a consequence of different light diffusion that passes through a material …”

“…When considering this results, it was taken into account that after freeze-drying, free water from raspberry is replaced by air, so the variations in red color and lightness can be a consequence of different light diffusion that passes through a material. 53 As for the rehydration capacity, the smallest difference between freeze-drying and convective drying of raspberry was reached with fresh raspberry convectively dried at 60 C air temperature and air velocity of 1.5 mÁs −1 . This result…”