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The process of lipid crystallization influences the characteristics of lipid. By changing the chemical composition of the lipid system, the crystallization behavior could be controlled. This review elucidates the internal factors affecting lipid crystallization, including triacylglycerol (TAG) structure, TAG composition, and minor components. The influence of these factors on the TAG crystal polymorphic form, nanostructure, microstructure, and physical properties is discussed. The interplay of these factors collectively influences crystallization across various scales. Variations in fatty acid chain length, double bonds, and branching, along with their arrangement on the glycerol backbone, dictate molecular interactions within and between TAG molecules. High-melting-point TAG dominates crystallization, while liquid oil hinders the process but facilitates polymorphic transitions. Unique molecular interactions arise from specific TAG combinations, yielding molecular compounds with distinctive properties. Nanoscale crystallization is significantly impacted by liquid oil and minor components. The interaction between the TAG and minor components determines the influence of minor components on the crystallization process. In addition, future perspectives on better design and control of lipid crystallization are also presented.

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The presence of minor components represents a challenging problem in spectrophotometric analysis of pharmaceuticals. If one component has a low absorptivity or present in a low concentration compared to the other components, this will hinder its quantitation by spectrophotometric methods. Continuous Wavelet Transform (CWT) as a signal processing technique was utilized to figure out a solution to such a problem. A comparative study was established between traditional derivative spectrophotometry (Numerical Differentiation, ND) and CWT to indicate the advantages and limitations of each technique and possibility of solving the problem of minor components. A mixture of ibuprofen (IBU) and phenylephrine (PHE) with its degradation products forming a ternary mixture was used for comparing the two techniques. The two techniques were applied on raw spectral data and on ratio spectra data resulting in four methods, namely ND, CWT, Derivative Ratio-Zero Crossing (DRZC) and Continuous Wavelet Transform Ratio-Zero Crossing (CWTR-ZC) methods. By comparing the results in laboratory prepared mixtures, CWT technique showed advantages in analysis of mixtures with minor components than ND. The proposed methods were validated according to the ICH guideline Q2(R1), where their linearity was established with correlation coefficient ranging from 0.9995 to 0.9999. The linearity was in the range 3-40 µg/mL for PHE in all methods, while for IBU it was 20-180 and 30-180 µg/mL in CWT and ND methods, respectively. The CWT methods were applied for quantitative determination of the drugs in their dosage form showing the ability of the methods to quantitate minor components in pharmaceutical formulations.

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Natural spider silk with extraordinary mechanical properties is typically spun from more than one type of spidroin. Although the main components of various spider silks have been widely studied, little is known about the molecular role of the minor silk components in spidroin self-assembly and fiber formation. Here, we show that the minor component of spider eggcase silk, TuSp2, not only accelerates self-assembly but remarkably promotes molecular chain alignment of spidroins upon physical shearing. NMR structure of the repetitive domain of TuSp2 reveals that its dimeric structure with unique charged surface serves as a platform to recruit different domains of the main eggcase component TuSp1. Artificial fiber spun from the complex between TuSp1 and TuSp2 minispidroins exhibits considerably higher strength and Young's modulus than its native counterpart. These results create a framework for rationally designing silk biomaterials based on distinct roles of silk components.

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n-Alkanes and n-alkenes are components of the unsaponifiable fraction of an olive oil. These were analysed by GC on-column analysis and are here proposed as an additional tool to certify the origin, authenticity, traceability and chemical quality of olive oil produced in the Reggio Calabria province (South Italy). Nine cultivars were studied: Cassanese, Coratina, Itrana, Leccino, Nociara, Ottobratica, Pendolino, Picholine and Sinopolese grown in the region of Calabria (South Italy). n-Alkanes in the range from 21 to 35 chain carbon atoms and alkenes in the range from 23:1 to 25:1 chain carbon atoms were found with the following elution order: heneicosane (C21), docosane (C22), tricosene (C23:1), tricosane (C23), tetracosene (C24:1), tetracosane (C24), pentacosene (C25:1), pentacosane (C25), hexacosane (C26), eptacosane (C27), octacosane (C28), nonacosane (C29), triacontane (C30), entriacontane (C31), dotriacontane (C32), tritriacontane (C33), tetratriacontane (C34), pentatriacontane (C35). The oil of all cultivars showed a decreasing trend in total n-alkane and n-alkene content, with the oil of Sinopolese showing the highest content, varying from 328.50 to 214.00 mg/kg. Odd-chain alkanes predominated over even-chain n-alkanes, and tricosane, tetracosane and pentacosane were the most represented alkanes. Cultivar and harvest date significantly influenced the n-alkane and n-alkene content. These findings can be useful to distinguish different olive cultivars and to decide the fruit harvest date for the oil of the Reggio Calabria province (South Italy). A daily quantity of 30 g of olive oil of the Sinoplese cv (the one with the highest n-alkane and n-alkene content) was found to be in accordance with the suggestions of the European Agency for the evaluation of medicinal products Committee for veterinary medicinal products and biogenic hydrocarbons intake for the human diet.

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Comparative study of the spectrophotometric strategies utilizing the isoabsorptive point present in overlapped absorption spectra of ciprofloxacin and fluocinolone acetonide in their recently delivered co-formulation, was presented. Four spectrophotometric approaches were developed, dependent on the determination of the leveling effect of isoabsorptive point in their zero order absorption spectra or its manipulated form ratio spectra as it retains an isosbestic point. The proposed strategy was based on determination of the total concentrations of the proposed drugs at iso-point, either via zero order or ratio spectra, while one of the recommended methods determined the concentration of the major component, so the concentration of the minor component was obtained by differentiation. The first, second and third methods are utilizing isoabsorptive point at zero order absorption spectrum to quantify total concentration of the cited component, while the major component could be selectively determined using either absorbance at its maxima (IsoPD0-D0max), or area under the peak method (IsoPD0-AUC), or first derivative technique (IsoPD0-D1). The fourth method is ratio manipulated isoabsorptive point in ratio spectrum, namely the amplitude modulation method (AM), using an unified regression equation for the total and major component concentrations, separately. The four methods were applied practically for the analysis of the binary mixtures of ciprofloxacin hydrochloride (CIP) and fluocinolone acetonide (FLU) in a recently otic solution form in challengeable ratio12:1respectively, without the need of any previous stages such as separation, dilution or standard addition. The methods were successfully validated as per ICH guidelines. The outcomes data gained from those submitted techniques were statistically assimilated with official ones. However, no radical differences were noticed.

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In the present study, a novel hyphenation of ultrafiltration (UF), high-speed countercurrent chromatography (HSCCC), and high-performance liquid chromatography (HPLC) was developed for comprehensive profiling and characterization of the minor tyrosinase inhibitors from Gastrodia elata (GE). A small quantity of GE extract was first fractionated by HSCCC, using elution solvents with a wide range of polarities to enrich minor compounds; then, the fractions were profiled by UF-HPLC to generate a comprehensive 2D chromatogram of the distribution of bioactive components. To determine the binding affinities of these bioactive components, the binding degree (BD%) was calculated by peak area reduction, in which a higher BD% indicates a higher binding affinity to tyrosinase. Among the 212 metabolites, 49 were identified as tyrosinase ligands, 17 of which showed high binding affinity. According to the 2D chromatogram, these 17 candidates were isolated by semiprep-HPLC for characterization of their structure using off-line hyphenated ultraviolet (UV), electron ionized mass spectrometry (EIMS), proton nuclear magnetic resonance (1H NMR). Their activities were further validated by functional assays. In conclusion, the approach developed here can comprehensively identify both major and minor bioactive constituents from natural products, and provide meaningful suggestions to direct further research. Compared to conventional approaches, this approach, developed by hyphenating several techniques, is a highly efficient means for comprehensive profiling of potent minor compounds extracted from natural products.

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NMR analysis of foods frequently suffers from a problem of dynamic range, which limits the detection of minor components due to the huge signals of water and major components such as sugars. In the present study, we propose a new method named as 'broadband WET'. This pulse scheme was applied to persimmon fruit juice for saturating the resonances of water and sugars, which covered a broad bandwidth. In comparison with the conventional solvent suppression methods such as WET and DPFGSE-WATERGATE, it was shown that broadband WET provided highly selective suppression of resonances covering an extensive bandwidth and quantitative signals of minor components without distortion. The proposed method is suitable to detect quantitative signals of the minor components with a high sensitivity.

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