Unraveling the relationship between conditions of ultrasonic‐assisted extraction of chia mucilage and viscosity

Abstract

BACKGROUND The application of chia mucilage still remains restricted due to the difficulty in achieving high extraction yields. The effect of ultrasonic‐assisted extraction (UAE) conditions (temperature, seed:water ratio and time) on the rheological properties of chia mucilage extracts and the relation to the proportion of translucent phase (TP) and opaque phase (OP) of the mucilage in the extract were evaluated. RESULTS UAE allowed the efficient extraction of chia mucilage from chia seeds. The desired overall optimal combination to maximize both yield and apparent viscosity was achieved at a seed:water ratio 1:10, a temperature of 25.3 °C and 53.7 min extraction time; the optimal conditions to obtain the maximum yield and minimum apparent viscosity were a seed:water ratio close to 1:20, temperature of 48.8 °C and 208.4 min extraction time. CONCLUSION The results obtained in the present work demonstrated that the differences in rheological properties of chia mucilage extracts are due to the extraction methods used. Therefore, it is possible to modulate the extraction conditions in order to obtain different characteristics of the mucilage, maintaining a high extraction yield. © 2022 Society of Chemical Industry.

Prospects of using non-thermal technologies for chia seed mucilage extraction

“…Even some reports are available with the use of response surface methodology (RSM) to understand the impact of these factors on techno-functional properties. 20,27,56,57 Interesting facts revealed from a review that hydration conditions have more impact on the yield of mucilage while the proximate composition is affected by the extraction and recovery method. 42 However, a review by Chiang et al 42 has explained the impact of the literature available up to 2021.…”

“…21,27,28,40,43,51,61 It is interesting to study the mechanism of reduction of mucilage yield at higher hydration time with increased temperature in the future. 56 According to the reports of Saporittis et al , 57 along with an increase in extraction time from 30–210 minutes, using a magnetic stirrer followed by 3 minutes of UAE has significantly affected the yield of mucilage. However, it was revealed that at lower extraction time, the yield was independent of the temperature, but along with an increase from temperature 25–65 °C, yield became more temperature dependent while extracting mucilage with ultrasound (3 minutes of treatment time).…”

“…However, it was revealed that at lower extraction time, the yield was independent of the temperature, but along with an increase from temperature 25–65 °C, yield became more temperature dependent while extracting mucilage with ultrasound (3 minutes of treatment time). 57 Longer stirring time, along with higher temperature, also affects the apparent viscosity of the mucilage, and modifying its molecular structure also impacts the apparent viscosity. 15,58,62 While considering better methods for higher mucilage yield from the literature, it is important to consider the impact of yield calculation, the impact of pH, hydration ratio, temperature, hydration time, method of separation, and the variety of chia seeds.…”

“…28 Similar observations of three different layer formations during centrifugation were confirmed by the other researchers. 15,21,35,57,64,79 A recent report, which used ultrasound and centrifugation, again explained the formation of two different phases (opaque and translucent phase) but correlated the ratios of translucent to opaque with the initial seed:water ratio during extraction and its impact on apparent viscosity. 57 This also provided new insights about the direction for future optimization with non-thermal technologies.…”

“…15,21,35,57,64,79 A recent report, which used ultrasound and centrifugation, again explained the formation of two different phases (opaque and translucent phase) but correlated the ratios of translucent to opaque with the initial seed:water ratio during extraction and its impact on apparent viscosity. 57 This also provided new insights about the direction for future optimization with non-thermal technologies. The yield of mucilage also differed upon mixing both phases and discarding the transparent phase after centrifugation.…”