Isolation of xanthones from adventitious roots of St. John’s Wort (Hypericum perforatum L.) and their antioxidant and cytotoxic activities

In this phytochemical study, 5 xanthones, 1,3,5,6-tetrahydroxyxanthone [1], 1,5,6-trihydroxy-3-methoxyxanthone [2], ferrxanthone [3], brasilixanthone B [4], and neolancerin [5] were isolated from adventitious roots of St. John’s wort (Hypericum perforatum L.). Compound 1–5 were evaluated for antioxidant activities using the intracellular reactive oxygen species (ROS) radical scavenging 2′,7′-dichlorfluorescein-diacetate (DCFDA) assay and for cytotoxic activity against the HL-60 human promyelocytic leukemia cells. Among them, compound 1–4 exhibited scavenging activity with inhibition values of 27.4–33.2% at 10 μM; compound 1, 2, and 4 reduced the viability of HL-60 cells significantly, with IC₅₀ values of 31.5, 28.9, and 27.7 μM, respectively.     

Gas sources in chemical leavening and other baker’s yeast substitutes: lessons from patents and science

Baker’s yeast produces carbon dioxide during dough fermentation, which gives bakery foods with expanded volume. This review covers gas sources other than baker’s yeast according to information disclosed in patents and supported by scientific literature. Inventors had more interest in gas injection in dough, mainly carbon dioxide, than gas-releasing agents available in chemical leavening, so-called baking powder, with 58 and 43 patented inventions, respectively. For chemical leavening, 20 gas-releasing agents were proposed, including 11 patented and 9 non-patented agents like sodium bicarbonate, the most popular. Other gas-releasing agents included miscellaneous salts of carbonate and bicarbonate (ammonium; calcium; magnesium; potassium) as well as compounds like hydrogen peroxide and, more recently, glutamic acid. Coatings were patented to protect sodium bicarbonate towards moisture and delay its action in dough. Recent trends include aerosol dough and flavourful sodium-free gas-releasing agents.     

Bisphenol A diglycidyl ether (BADGE) migrating from packaging material ‘disappears’ in food: reaction with food components

Bisphenol A diglycidyl ether (BADGE) is widely used as a monomer for coatings and adhesives for food-contact applications. Previous publications indicate that, after migration from packaging into foodstuffs, BADGE undergoes various reactions with unidentified food components. In order to elucidate the fate of BADGE, losses were determined after incubation with different foodstuffs and food components. Food proteins were identified as the main reaction partner with BADGE. Adduct formation was found with nucleophilic side-chains of amino acids. In vitro, cysteine exhibited significant activity. The previously reported occurrence of methylthio-derivatives of BADGE in foodstuffs was shown to originate from the reaction of BADGE with methionine. BADGE-methylthio derivatives can, therefore, be used as marker substances in foodstuffs for protein reactions with BADGE. The reported results offer a new viewpoint on the evaluation of BADGE migration. The hydrolysis and hydrochlorination derivatives subject to European legislation make up only a fraction of the totally migrated BADGE, and a further concern is that the toxic or allergenic potential of the protein adducts are unknown.     

Kinetics Modeling of Mass Transfer Using Peleg’s Equation During Osmotic Dehydration of Seedless Guava (<Emphasis Type="Italic">Psidium guajava</Emphasis> L.): Effect of Process Parameters

Peleg’s equation was used to study the effect of process parameters on kinetics of mass transfer in terms of solids gain and water loss during osmotic dehydration using 30–50% (w/w) sucrose solution at 30, 40 and 50 °C. The experimental data were successfully fitted employing Peleg’s equation with the coefficient of determination (R ²) higher than 0.88, the root mean square error, and the mean relative percentage deviation modulus (E) of less than 0.003% and 6.40% for all treatments, respectively. In all cases, initial mass transfer rate parameter (K ₁) decreased significantly (p < 0.05) as the solution concentration and solution temperature increased suggesting a corresponding increase in the initial mass transfer rate. Initial mass transfer rate followed an Arrhenius relationship which showed that solids gain had the highest temperature sensitivity (E _a = 21.93–33.84 kJ mol⁻¹) during osmotic dehydration. Equilibrium mass transfer parameter (K ₂) decreased significantly (p < 0.05) as solution concentration increased demonstrating that the equilibrium solid and water contents increased with increase in solution concentration. The equilibrium solid and water contents were also estimated adequately using Peleg’s equation (R ² > 0.78). The results of this work allow estimating the kinetics of mass transfer during osmotic dehydration in order to obtain products with determined solid and water contents.     

Physical factors in the hermetic SuperGrainBag® and effect on the larger grain borer [Prostephanus truncatus (Horn) (Coleoptera: Bostrichidae)] and aflatoxin production by Aspergillus flavus during the storage of ‘Obatanpa’ maize (Zea mays L.) variety

Controlling invasive pests and aflatoxin production by moulds in stored grains is a global challenge to food security and public health, particularly in Africa. Food storage systems are designed to provide constraints to spoilage organisms by presenting mechanical barrier or unfavourable atmospheric conditions to their growth and productivity. This study examined the physical factors generated in hermetic SuperGrainBags^® during the storage of ‘Obatanpa’ variety of maize (Zea mays L.) and the effect on growth of the larger grain borer Prostephanus truncatus (Horn) and aflatoxin contamination by Aspergillus flavus. Cultured P. truncatus or A. flavus was introduced into 1.5 kg of the dried maize and stored in either hermetic SuperGrainBags^® or non-hermetic polypropylene bags. The hermetic conditions elicited an increase in the interstitial temperature (ca. 27 °C) but a decrease in the relative humidity (<70%), oxygen concentration (<6.4%) and the grain moisture content (<13.7%), the combined effects of which inhibited growth of the insects and aflatoxin production by the moulds. Total mortality of P. truncatus occurred after 52 d of storage in the SuperGrainBags^® while aflatoxins concentration remained within safe limits for human consumption. In contrast, there was proliferous growth of P. truncatus and significant increase in aflatoxin concentration to lethargic levels within the polypropylene bags where temperature, relative humidity and grain moisture increased significantly. Accordingly, grain damage and weight loss percentages were significantly high in the polypropylene bags while that in the SuperGrainBags^® were negligible. Altogether, the SuperGrainBags^® better preserved the maize grain quality and safeguarded it against health risks than the polypropylene bags.