Insight into the effect of fatty acid composition on the texture of French fries

BACKGROUND

Several researchers have reported that the texture of fries is affected by the fatty acid composition of oil, although the mechanism of this effect is not clear. In this regard, fries were fried in refined rapeseed oil and fully hydrogenated rapeseed oil with diverse proportions (0%, 20%, 40%, 60%, 80% and 100%) and were analyzed based on the content of moisture and oil, texture, thermal properties, crystalline properties and microstructure.

RESULTS

The outcomes presented that fries fried in fully hydrogenated oil had less oil absorption and moisture loss than those fried in refined oil. The results from the texture analyzer, differential scanning calorimetry and X-ray diffraction showed that hardness, enthalpy and relative crystallinity increased with an increase in the proportion of fully hydrogenated oil. However, the peaks of starch-lipid complexes were hardly observed during frying. Furthermore, scanning electron microscopy results displayed that some physically trapped fat was observed in fries fried in mixed hydrogenated oil. Stereomicroscope images showed that the crust thickness of the fries increased slightly with an increase in the proportion of fully hydrogenated oil.

CONCLUSION

Overall, the upsurge in crust thickness and oil crystals was responsible for an increase in the hardness of the fries. This indicated that the texture of fries can be manipulated by altering the fatty acid composition of the oil. © 2021 Society of Chemical Industry.

Understanding the structural diversity of chitins as a versatile biomaterial

Chitin is one of the most abundant biopolymers, and it has adopted many different structural conformations using a combination of different natural processes like biopolymerization, crystallization and non-equilibrium self-assembly. This leads to a number of striking physical effects like complex light scattering and polarization as well as unique mechanical properties. In doing so, chitin uses a fine balance between the highly ordered chain conformations in the nanofibrils and random disordered structures. In this opinion piece, we discuss the structural hierarchy of chitin, its crystalline states and the natural biosynthesis processes to create such specific structures and diversity. Among the examples we explored, the unified question arises from the generation of completely different bioarchitectures like the Christmas tree-like nanostructures, gyroids or helicoidal geometries using similar dynamic non-equilibrium growth processes. Understanding the in vivo development of such structures from gene expressions, enzymatic activities as well as the chemical matrix employed in different stages of the biosynthesis will allow us to shift the material design paradigms. Certainly, the complexity of the biology requires a collaborative and multi-disciplinary research effort. For the future's advanced technologies, using chitin will ultimately drive many innovations and alternatives using biomimicry in materials science. This article is part of the theme issue 'Bio-derived and bioinspired sustainable advanced materials for emerging technologies (part 1)'.

Benzodithiophene-Fused Perylene Bisimides as Electron Acceptors for Non-Fullerene Organic Solar Cells with High Open-Circuit Voltage

Tandem-junction organic solar cells require solar cells with visible light photo-response as front cells, in which an open-circuit voltage (V_oc ) above 1.0 V is highly demanded. In this work, we are able to develop electron acceptors to fabricate non-fullerene organic solar cells (NFOSCs) with a very high V_oc of 1.14 V. This was realized by designing perylene bisimide (PBI)-based conjugated materials fused with benzodithiophene, in which Cl and S atom were introduced into the molecules in order to lower the frontier energy levels. The fused structures can reduce the aggregation of PBI unit and meanwhile maintain a good charge transport property. The new electron acceptors were applied into NFOSCs by using Cl and S substituted conjugated polymers as electron donor, in which an initial power conversion efficiency of 6.63 % and a high V_oc of 1.14 V could be obtained. The results demonstrate that the molecular design by incorporating Cl and S atom into electron acceptors has great potential to realize high performance NFOSCs.