Sensory Profiling and External Preference Mapping of Pre-Thickened Water Products for Dysphagia

Dysphagia is a dysfunction of the swallowing system and thickened beverages are widely prescribed as a treatment. The objective of this study was to determine the sensory characteristics of pre-thickened water products and determine sensory drivers of liking for those types of products. Pre-thickened water products (two starch-based and two gum-based) were tested in both nectar and honey thick versions. Based on product availability, one product was neutral water, and the others were water with lemon flavoring added. The sensory characteristics of the products were evaluated with a highly trained descriptive panel, and the viscosity of the products was evaluated with both the Bostwick consistometer and the line spread test. Previously published consumer data was used to determine preference maps with the descriptive data. All lemon-flavored products had similar flavor characteristics, except the Thick & Easy Clear that had a less lemon-related flavor than the others. After excluding the lemon-related flavor characteristics, all pre-thickened products had similar “base flavor” notes, no matter whether the products were starch-based or gum-based. This contrasts with literature, which reports differences in flavor of thickened beverages prepared using thickening agents. The thickness of the products varied between nectar and honey thickness, but also varied among products that were stated to be at the same level of thickness. External preference mapping showed that both lemon-related flavor and a thinner beverage texture are potential drivers of consumers acceptance of the product, which was expected based on other studies. In conclusion, pre-thickened beverages are good alternatives for self-mixed thickening agents but a standard for thickness should be agreed on and used by manufacturers.

Synthesis of Novel Aqua ƞ4-NNNO/Cu(II) Complexes as Rapid and Selective Oxidative Catalysts for O-Catechol: Fluorescence, Spectral, Chromotropism and Thermal Analyses

A new tetradentate Schiff base (SB), (E)-4-fluoro-2-(1-((2-(piperazin-1-yl)ethyl)imino)ethyl)phenol, was synthesized from condensation of 2-(1-piperazinyl)ethylamine and 5-fluoro-2-hydroxyacetophenone. This ligand was coordinated with three copper(II) salts (CuCl2, CuBr2 and Cu(NO3)2⸱3H2O) separately, giving rise to new neutral water-soluble Cu(II)/ƞ4-NNNO complexes (1–3). The new materials were fully characterized by standard spectroscopic, elemental, thermal, electronic, absorption, and fluorescence analyses. The chromotropism investigation of the aqueous solutions of the complexes revealed notable outcomes. A turn off-on halochromism effect was observed, both in the acidic and basic mediums. The green-colored solution was changed to colorless (off) upon the addition of HCl, while the initial green color was reversibly restored (on) after the addition of NaOH. On the other hand, bathochromic solvatochromism shifts were noticed in various solvents. Interestingly, complex 2 displayed a remarkable blue fluorescence shift (Δλ = 90 nm) when compared to its SB ligand. The oxidation capability of the three complexes was successfully demonstrated for the conversion of o-catechol to o-benzoquinone in aqueous solutions and in the presence of H2O2, an environmentally friendly oxidant, under mild reaction conditions.

Roles of bicarbonate ion in the deterministic Z-scheme and the stochastic murburn model for the light reaction of oxygenic photosynthesis

Bicarbonate ion has been proposed as a potential source for electrons/O-atom in the light reaction of oxygenic photosynthesis, both in the pre-Zscheme era and in recent times. In the light of murburn concept being mooted as a viable explanation for photophosphorylation, we present substantial theoretical analysis which supports the proposal that: (i) Bicarbonate ion can serve as a viable source of electrons to electron-discharged photosystems or other positively-charged intermediates (formed after photo-activation) in thylakoids. This is because electron abstraction from bicarbonate anion [(a). HCO3- → CO2 + *OH + e-; ° ≈ 491 kJ/mol] is more viable with respect to the classical alternative/available option like the neutral water molecule [(b). H2O → H+ + *OH + e-; ° ≈ 527 kJ/mol]. (ii) The hydroxyl radical directly produced in reaction (a) in conjunction with other diffusible reactive oxygen species (DROS) sponsor murburn phosphorylation cycles and/or dismutations/cross-reactions. Spontaneous involvement/formation of molecular oxygen in several such discretized bimolecular reactions is also a kinetically viable process. Therefore, the incorporation of an O-atom from bicarbonate into the oxygen gas evolved in the light reaction is a tenable outcome of the stochastic/statistical murburn model. We provide the pertinent equations and abrogate the bioenergetic calculations.

Effect of fermentation media and time on physicochemical and sensory properties of soybean powders

Fermentation improves quality of food, and is exploited in processing soymilk powder. Unfortunately, there is no unified fermentation procedure for producing powdered soymilk in Nigeria. A fermentation condition to produce high nutritional and most acceptable powdered soymilk is ideal for Nigerians. This study evaluated the effect fermentation media and time on physicochemical and sensory properties of powdered soymilk. Seven batches (600 g each) of soybean seeds were fermented, the first three in neutral water, sample A for 4 h, B for 16 h in the same water, and C for 16 h but changing the water every 4 h. The next two were fermented in alkaline solution for 16 h, D in the same water, and E with changing the water every 4 h. The last two were fermented for 16 h in acidic solution, Fin the same solution and G with changing the water every 4 h. The beans were processed into cooked soy flour and analyzed for physicochemical and sensory properties. Fermentation enhanced better quality than soaking; fermentation time and medium pH significantly (p < 0.05) induced variations in quality of the powder. Soaking produced soy powder with highest carbohydrate (44.47 %) and fibre (1.355%) but significantly (p < 0.05) low in protein, minerals and crude fat. Continuous 16-h fermentation in the same medium produced soy powders with lowestphytochemical contents. Soaked (4 h) soybean in neutral water (A) produced powder with 39.50% protein, 44.47% carbohydrates, 1.35% fibre, 5.58% fat and 2.75% ash while continuous fermentation for 16 h in the same water produced powder (B) with 42.47% protein, 41.71% carbohydrate, 1.22% fibre, 5.81% fat and 2.42% ash. Continuous 16-h fermentation was better than changing the medium; and neutral medium was better than acidic and alkaline medium. All the soy powder high sensory scores (≥ 5) and were acceptable to the panelists. Thus, 16-h continuous fermentation in neutral medium was more cost effective and produced soybean powder of better quality than fermenting in alkaline and acidic media. Key words: fermentation time, quality, soaking media, soybean powders

Icilio Guareschi and his amazing “1897 reaction”

Organic chemistry honors Icilio Guareschi (1847–1918) with three eponymic reactions, the best known ones being the Guareschi synthesis of pyridones and the Guareschi–Lustgarten reaction. A third Guareschi reaction, the so-called “Guareschi 1897 reaction”, is one of the most unusual reactions in organic chemistry, involving the radical-mediated paradoxical aerobic generation of hydrocarbons in near-neutral water solution. A discussion of the mechanism of this amazing reaction, the only metal-free process that generates hydrocarbons, and the implications of the approach in biology and geosciences mirrors the multifaceted scientific personality of the discoverer. Thus, Guareschi’s eclectic range of activities spans a surprising variety of topics, overcoming the boundaries of the traditional partition of chemistry into organic, inorganic, and analytical branches and systematically crosses the divide between pure and applied science as well as between the history of chemistry and the personal contributions to its development.