Animal fat tissue (that is, pork or beef fat) is composed of liquid and solid fat incorporated in a network of connective tissue. Hence, their rheological and thermal properties may differ significantly from plant-derived fats. Specifically, animal fats have elastic and melting properties that give rise to not only a certain comminution behavior during processing, but also provide meat products such as sausages with certain organoleptic properties. To mimic key properties of animal fat tissue with plant-derived materials, a new structuring approach was used. Canola oil was mixed with <30% (w/w) of fully hydrogenated canola oil at 65°C, hot-emulsified with a soy protein suspension (8%, w/w) at a lipid content of 70% (w/w) using a high-shear disperser, and cooled to 37°C. The concentrated, emulsified fat crystal networks were then incubated with transglutaminase for 1 hr to induce protein crosslinking. Microscopy images showed that samples were composed of tightly packed lipid particles with regions of coalesced or unemulsified lipids appearing at higher solid fat concentrations. Texture analysis and rheological measurements showed that crosslinked samples possessed elasticities that decreased with increasing solid fat concentration. Above 30% solid fat, matrices reverted back to exhibiting a mainly plastic behavior. Results were attributed to the formation of either a droplet-filled protein network, a particulate fat crystal network, or a mixture thereof. Taken together, results show that plant-based crosslinked emulsified fat crystal networks are able to mimic mechanical properties of animal fat provided that not too much solid fat (<30% in this study) is used. This makes them useful for the manufacture of meat products or analogues.Practical Application: This study introduced a new structuring approach to mimic properties of animal fat tissue with only plant-derived materials. The structured lipids can, for example, be used for the manufacture of processed meat analogues.

Model orange juice solutions containing 0.024 mM thiamin hydrochloride were stored for up to 8 weeks at 35 degrees C in amber glass containers. Volatiles were evaluated, primarily, using gas chromatography (GC) with olfactometry but also with flame ionization detector, pulsed-flame photometer detector (PFPD) (sulfur specific), and MS detection. Both 2-methyl-3-furanthiol (MFT) and its dimer, bis(2-methyl-3-furyl) disulfide (MFT-MFT) were identified thus confirming that thiamin could serve as the precursor to these potent off-flavors in thermally degraded citrus juices. Thirteen aroma active components were observed. MFT and MFT-MFT were observed after only a few days storage, and produced 33% of the total aroma activity after 7 d storage. Both compounds were observed olfactometrically earlier than they could be detected using PFPD. Other aroma-active compounds included 4,5-dimethylthiazole (skunky, earthy), 3-thiophenethiol (meaty, cooked), 2-methyl-4,5-dihydro-3(2H)-thiophenone (sour-fruity, musty, green), 2-acethylthiophene (burnt), 2-formyl-5-methylthiophene (meaty), and 2-methyl-3-(methyldithio) furan (meaty).

The incorporation of novel plant-based proteins into foods is often challenging due to an unacceptable bitter sensation. Typically, a combination of electrostatic and hydrophobic forces contributes to the proteins' bitterness. The current study therefore focuses on the development of electrical properties on cationic plant proteins to reduce their overall bitterness in order to improve the perceived sensorial acceptance. As such, we utilized a simple mixing process to induce complex coacervation of oppositely charged biopolymers under acidic conditions. Pea and potato protein stock solutions were mixed with apple pectin (DE 71%) solutions at various biopolymer ratios to modulate the electrical, rheological, and sensorial properties of the complexes. Whey protein hydrolyzate was used as a control sample. Surface charge measurements revealed a transition from positive to negative values as the pectin concentration was increased regardless of the plant protein, whereas stable dispersions without sedimentation were observed above a critical pectin : protein ratio of 1. Low and intermediate biopolymer ratios (<1) promoted aggregation and led to rapid sedimentation. Sensory evaluation showed that bitterness scores depended on protein type and decreased from pea protein > potato protein > whey protein. Moreover, bitter off-notes were increasingly reduced with increasing pectin : protein ratios; however, high dispersion viscosities above 0.05 Pa s led to undesirable texture and mouthfeel of the biopolymer dispersions. Our results might have important implications for the utilization of novel plant proteins in food and beverage applications.