Effect of Anthocyanins Extracted from Peanut Skins, Roselle Calyces and Outer Peels of Onions on Quality and Colour Stability of Yoghurt Beverages during Storage

Abstract

Anthocyanin have been used as a natural food colourant and as a source of natural antioxidants. Aqueous extracts of dried roselle calyces, outer peels of yellow onions, and peanut skins were used as sources of anthocyanin and other functional components such as phenolic and flavonoid compounds to fortify yoghurt beverages. Antioxidants, total phenolics, total flavonoids and anthocyanin were estimated in the plant extracts. Colour stability was evaluated in yoghurt beverages fortified with anthocyanin extracted during the storage period at 4±1°C for three weeks. The highest amount of total phenolic content was observed in peanut skin extract (1.645 mgml -1 ), followed by dry outer peels of onions (1.5 mgml -1 ) and roselle calyces (1.3 mgml -1 ). Dry outer peels of onions showed the highest flavonoid content compared with peanut skin and roselle calyces extract. The highest amount of total anthocyanin was observed in roselle calyces (3.877 mg 100 g -1 ), followed by aqueous extract of onions skin (0.635 mg 100 g -1 ). During the storage period at 4±1 °C for three weeks, yoghurt beverages physicochemical and functional properties had been evaluated. The anthocyanin improved the colour, appearance, and overall acceptability of fortified yoghurt beverages. The overall results suggested that it is possible to produce high-quality yoghurt beverages fortified by adding 0.2% extracts of dry peanut skins, dry roselle calyces, and dry outer peels of yellow onions, which obtaining colours degree of red-orange, cheery red, and orange-yellow, respectively, colour stability during the storage period at 4±1°C for three weeks.

Development of a probiotic low‐fat set yogurt containing concentrated sweet pepper extract

“…The average overall acceptance score of the yogurt samples at the beginning of the storage time was determined as 8.17, which decreased to 7.74 in the middle of storage and to 7.29 at the end of 21 days of cold storage. A decrease in the sensory score during storage has also been reported by other researchers (Khalifa & Gomaa, 2021 ; Salah et al., 2022 ). Mousavi et al.…”

“…The average overall acceptance score of the yogurt samples at the beginning of the storage time was determined as 8.17, which decreased to 7.74 in the middle of storage and to 7.29 at the end of 21 days of cold storage. A decrease in the sensory score during storage has also been reported by other researchers (Khalifa & Gomaa, 2021;Salah et al, 2022). Mousavi et al (2019) According to Table 1, the highest overall acceptance with a score of 8.31 was related to the control sample on the first day of the storage period, and the lowest with a score of 7.05 was related to the yogurt sample containing red CSPE on the 21st day of storage.…”

“…( 2009 ) also reported that yogurt fortified with 3% date fiber had similar total acceptability score as compared with control yogurt, and increasing date fiber to 4.5% caused a significant decrease in total acceptability. On the contrary, Khalifa and Gomaa ( 2021 ) reported an increase in overall acceptance score in yogurt drinks containing plant extracts from the dried roselle calyces, peanut skins, and outer peels of yellow onions.…”

Synbiotic Yogurt Fortified with Bawang Dayak (Eleutherine palmifolia) Extract

“…The increase in the value of L is followed by a decrease in the value of a*. As explained by Khalifa and Gomaa [37] that the highest a* value is found in the addition of extracts with the highest anthocyanin pigment, with the lowest a* in the least extract addition. Color changes in the product are caused by the anthocyanin levels in the product [38].…”