Effect of drying methods on bioactive compounds, nutritional, antioxidant, and antidiabetic potential of brown alga Durvillaea antarctica

Abstract

The effects of vacuum, solar, convective, infrared and freeze drying (VD, SD, CD, IRD, FD) on Durvillaea antarctica were evaluated in terms of nutritional composition, color, bioactive components, and antioxidant and anti-diabetic activities. Nutritional composition of the dried seaweeds scarcely varied, while a tendency to lose the reddish tone occurred. CDseaweed had highest phytochemical and vitamin contents, while FDsamples showed best retention of pigments. Both samples also exhibited the strongest antioxidant and antidiabetic activities. The highest essential amino acids and polyunsaturated fatty acids contents were found in IRDand SD-samples respectively. In general, FD and CD proved to be viable drying options for D. antarctica.Keywords: brown seaweed Durvillaea antarctica; drying methods; bioactive components; antidiabetic properties; amino acids; fatty acids USA) until analysis. All drying assays were performed in triplicate.FD of the fresh seaweeds (0.500 kg) was performed using a freeze-dryer (Virtis Advantage Plus, Gardiner, NY, USA). The sample was first frozen at -80 °C for 24 h, then placed horizontally onto two drying trays at a charge density of 6.08 kg/m 2 and dried in the primary drying phase programed from -50 to 20 °C followed by the secondary drying phase at 20 °C under vacuum (0.027 kPa) for 72 h. CD was performed in a convective dryer as described by Uribe et al.[10] at 60±0.2 °C with 1.200 kg fresh samples evenly arranged on two stainless steel trays at a load density of 6.28 kg/m 2 under a constant air flow of 1.5±0.2 m/s. VD was performed at 60±0.2 °C and 15 kPa in a vacuum oven (Memmert VO400, Schwabach, Germany) for 480 min with the samples (0.500 kg) placed on stainless steel trays at a load density of 4.13 kg/m 2 . SD was

Characterization of phytochemicals, minerals and in vitro medicinal activities of bael (Aegle marmelos L.) pulp and differently dried edible leathers

“…Though BH showed high retention (50.83%) of vitamin C, but the result is in agreement within the range of 44.28-63.85% previously reported by Chang et al (2006) and Chan et al (1997) for hot air dried tomatoes (I-Tien-Hung variety) and seaweed, respectively. Uribe et al (2019) also reported an increase by 11.05% of vitamin C in the convective dried brown alga. It can be concluded that the retention of vitamin C is also dependent on sample characteristics.…”

“…The maximum retention of δ-tocopherol was observed in BM (15.18%), while the same for γ-tocopherol was observed in BH (31.69%). The relative higher content of the tocopherol in BH and BM might be due to the fact that the occurrence of the tocopherol within the lipid segment of the samples; which by virtue shielded the thermal destruction of tocopherol (Uribe et al, 2018(Uribe et al, , 2019Van Hoed et al, 2009). The higher value of standard deviation for BH may have resulted from the uneven distribution of lipid segment and less uniform exposure to degrading drying conditions.…”

“…The traditional way of making leather is to dry the pulp in the sun, which is one of the easiest and cheapest methods. However, the main problems associated with this are uncertain climatic conditions, microorganisms, dust, dirt and insect infections that produce an inferior quality product in terms of hygiene (Uribe et al, 2019). Therefore, it is better to focus on other possible alternatives, mainly industrial methods like, microwave drying, hot air drying, and freeze drying which gives better yields in terms of production rate and quality of the leather.…”

Health-promoting activities of edible seaweed extracts from Chilean coasts: assessment of antioxidant, anti-diabetic, anti-inflammatory and antimicrobial potential

“…Seaweeds are often rich sources of PUFAs, especially high in P. orbicularis (52.63 g 100 g -1 of total fatty acid) 13 , Ulva spp. (41.94 g 100 g -1 of total fatty acid) 14 and D. antarctica (41.94 g 100 g -1 of total fatty acid) 15 . According to the review of Pina-Pérez et al, the mechanism of action of fatty acids as antimicrobials may be due to cell leakage derived from membrane damage.…”

“…Despite the fact that Chile has a great variety of seaweeds, especially edible kinds, Chilean seaweed has been little exploited. Most research about Chilean seaweed has focused on nutritional aspects 9,10,11 or selected chemical compounds of interest 6,12,13,14,15 . No previous study has investigated the bioactivities of Chilean seaweed extracts.…”