Profiling and Quantification of Anthocyanins in Purple-Pericarp Sweetcorn and Purple-Pericarp Maize.

Purple-pericarp sweetcorn accessions, derived from crossing purple-pericarp maize with white shrunken2 sweetcorn, were assessed for differences in anthocyanin profile at both sweetcorn eating stage and at full kernel maturity. The 'Tim1' sweetcorn line developed a similar total anthocyanin concentration to its 'Costa Rica' parent when assessed at sweetcorn-eating stage. At full maturity it surpassed the purple maize parent, but this was mainly due to the presence of starch diluting the anthocyanin concentration of the latter. The anthocyanin/colour relationship was affected by both total anthocyanin concentration and the ratio of cyanidin- to pelargonidin-based anthocyanins. Malonylation of anthocyanins was also found to vary and did not appear to be linked with either cyanidin:pelargonidin ratio or total anthocyanin concentration. In addition, anthocyanin synthesis was affected by kernel maturity at harvest, with colour development increasing in conjunction with a progression of anthocyanin development across the kernel surface. Pigmentation was present in the aleurone, pericarp and vitreous endosperm of kernels of the purple-pericarp maize parent and purple-pericarp sweetcorn accessions when fully mature, but pigmentation was only apparent in the pericarp at sweetcorn-eating stage. Importantly for consumers, anthocyanin pigmentation covered almost the entire kernel surface at sweetcorn-eating stage.

Breaking the tight genetic linkage between the a1 and sh2 genes led to the development of anthocyanin-rich purple-pericarp super-sweetcorn.

The existence of purple-pericarp super-sweetcorn based on the supersweet mutation, shrunken2 (sh2), has not been previously reported, due to its extremely tight genetic linkage to a non-functional anthocyanin biosynthesis gene, anthocyaninless1 (a1). Generally, pericarp-pigmented starchy purple corn contains significantly higher anthocyanin. The development of purple-pericarp super-sweetcorn is dependent on breaking the a1-sh2 tight genetic linkage, which occurs at a very low frequency of < 1 in 1000 meiotic crossovers. Here, to develop purple-pericarp super-sweetcorn, an initial cross between a male purple-pericarp maize, 'Costa Rica' (A1Sh2.A1Sh2) and a female white shrunken2 super-sweetcorn, 'Tims-white' (a1sh2.a1sh2), was conducted. Subsequent self-pollination based on purple-pericarp-shrunken kernels identified a small frequency (0.08%) of initial heterozygous F3 segregants (A1a1.sh2sh2) producing a fully sh2 cob with a purple-pericarp phenotype, enabled by breaking the close genetic linkage between the a1 and sh2 genes. Resulting rounds of self-pollination generated a F6 homozygous purple-pericarp super-sweetcorn (A1A1.sh2sh2) line, 'Tim1'. Genome sequencing revealed a recombination break between the a1 and yz1 genes of the a1-yz1-x1-sh2 multigenic interval. The novel purple-pericarp super-sweetcorn produced a similar concentration of anthocyanin and sugar as in its purple-pericarp maize and white super-sweetcorn parents, respectively, potentially adding a broader range of health benefits than currently exists with standard yellow/white sweetcorn.

Folate vitamers in the Australian green plum: Through growth and ripening and across locations.

The green plum is a native fruit of Australia that grows on the tree Buchanania obovata. This study aimed to confirm the high level of folate in green plums by analyzing a large number of ripe samples from multiple locations and to understand how folate vitamers change as the fruit grows through maturity stages. This study analyzed green plums for five vitamers of folate, H4folate, 5-CH3-H4folate, 5-CHO-H4folate, 10-CHO-PteGlu, and PteGlu (folic acid) using a stable isotope dilution assay on a liquid chromatograph mass spectrometer (LC-MS). Green plums were tested from four locations, two harvests and five maturity stages. Another 11 ripe samples, each from different tree clumps from one location, were also tested as were ripe red-colored green plums. The results show the 5-CH3-H4folate in green plum increases and accumulates in the fruit through development, ripening and senescence. The ripe green plums contain between 82.4 ± 5.5 and 149.4 ± 10.7 µg/100 g Fresh Weight (FW). The red-colored green plums are even higher in folate, with total folate measured as 192.5 ± 7.0 and 293.7 ± 27.4 µg/100 g FW, and further analysis of them is suggested. There is some variation in amounts of folate between fruit from different locations and sets of trees, but all ripe green plums tested are considered good dietary sources of folate.

Curcumin-Based Photosensitization, a Green Treatment in Inactivating Aspergillus flavus Spores in Peanuts.

Controlling microbial contamination in foods using effective clean and green technologies is important in producing food with less contaminants. This study investigates the effect of photosensitization treatment using naturally occurring curcumin on inactivating Aspergillus flavus spores on peanuts. Light dosages of 76.4 J/cm2 and 114.5 J/cm2 at 420 nm were employed in combination with curcumin concentrations from 25 to 100 µM. The inactivation efficiency of the treatment towards spores in suspension achieved a maximum 2 log CFU/mL reduction in viable spores with 75 µM of curcumin at a light dosage of 114.5 J/cm2 (p < 0.05). The in vivo study was then designed using the optimum conditions from the in vitro experiment. The photosensitization treatment at three different curcumin concentrations (50, 75, 100 µM) extended the shelf-life of raw peanuts by 7 days when treated with 75 µM of curcumin combined with a 114.5 J/cm2 light dosage and stored at 25 °C. The treatment effectively reduced average levels of aflatoxin B1 (AF-B1) on peanuts stored for 7 days at 25 °C from 9.65 mg/kg of untreated samples to 0.007 and 0.006 mg/kg for 75 and 100 µM curcumin (p < 0.05) respectively. The results show the potential use of curcumin-based photosensitization treatment in inactivating fungal growth and reducing AF-B1 concentration on raw peanuts.

Effect of Storage on the Nutritional Quality of Queen Garnet Plum.

Due to high perishability, plums are harvested at an early stage of maturity to extend postharvest storage life. Storage time and temperature can significantly affect the phytochemical and sugar composition of plums, altering their palatability and nutritional quality. In this study, variations in physiochemical properties (total soluble solids (TSS), titratable acidity (TA), color (chroma and hue angle)), phytochemical composition (total phenolic content (TPC), total anthocyanin content (TAC), and carotenoids), and sugars in three different tissues of the Queen Garnet plum (QGP) during storage at two common domestic storage temperatures (4 and 23 °C) were evaluated. There was an increase (p > 0.05) in TSS and a reduction (p < 0.05) in TA of the outer flesh at 23 °C. Chroma values of all the tissues reduced (p < 0.05) at 23 °C. At 4 °C, chroma values fluctuated between storage days. The TAC of the peel was the highest (p < 0.05) among the different tissues and continued to increase up to 10 days of storage at 23 °C (3-fold increase). At 4 °C, the highest (p < 0.05) TAC (peel) was observed after 14 days of storage (1.2-fold increase). TPC showed similar results. The highest (p < 0.05) TPC was recorded in the peel after 10 days of storage at 23 °C (2.3-fold increase) and after 14 days of storage at 4 °C (1.3-fold increase), respectively. Total carotenoids in the flesh samples at both storage temperatures were reduced (p < 0.05) after 14 days. Total sugars also decreased during storage. The results of the present study clearly showed that common domestic storage conditions can improve the nutritional quality of plums by increasing the content of bioactive anthocyanins and other phenolic compounds. However, the increase in phytochemicals needs to be counterbalanced with the decrease in total sugars and TA potentially affecting the sensory attributes of the plums.

Tecticornia sp. (Samphire)-A Promising Underutilized Australian Indigenous Edible Halophyte.

Salinization is gradually increasing over cropping soils and is challenging Governments in many countries, including Australia. There has been a high demand for utilizing arid and semi-arid land for sustainable food production. Currently, the main crops and forage plants are salt sensitive, while halophytes can tolerate a wide range of salinities. Samphire is an Australian indigenous edible halophyte and belongs to the genus Tecticornia. It is an underutilized, succulent plant growing on arid or semi-arid land. Most samphire species have a long history of use as food, but also as non-food (fodder and medicine), among indigenous communities in Australia, while scientific information is limited on their nutritional composition and potential bioactivity. The present study reports, for the first time, the nutritional composition, bioactive compounds (phytochemicals) and antioxidant capacity of six Australian grown samphire from different locations. The results showed that celosianin II and isocelosianin II could be identified as the predominant betalains (phytochemicals) in pigmented samphire species. Proximates and fiber varied significantly (p < 0.05) between the samphire species with a highest value of fiber of 46.8 g/100 g dry weight (DW). Furthermore, samphire could be identified as a valuable source of essential minerals and trace elements, such as iron (41.5 mg/100 g DW), magnesium (1.2 g/100 g DW) and sodium (16.7 g/100 g DW). The fatty acid profile, mainly palmitic, stearic, oleic, linoleic and α-linolenic acid, was similar among the studied species. Total phenolic content and DPPH-radical scavenging capacity were different (p < 0.05) between the six samphire samples. These initial results are very promising and indicate that Australian grown samphire may have the potential to be utilized as a functional food ingredient.

Low anthocyanin plum nectar does not impact cognition, blood pressure and gut microbiota in healthy older adults: A randomized crossover trial.

Queen Garnet plum (QGP), known for its high levels of anthocyanins, is a hybrid of the Japanese plum developed in Queensland, Australia. Anthocyanins provide the red, blue, and purple pigments in plants with demonstrated beneficial health effects. This study hypothesized that low-dose anthocyanin QGP intake will have a significant positive effect on cognition, blood pressure, and gut microbiota in healthy older adults. A randomized crossover trial was conducted to determine the effect and within subject variance on cognition and 24 hr. ambulatory blood pressure in older adults without cognitive impairment following daily consumption of 200 mL low-dose anthocyanin (5 mg/100 g) QGP nectar (intervention) or raspberry cordial (control). Secondary outcomes included inflammatory markers (C-reactive protein), nerve growth factor (BDNF), and gut microbiota (16S rRNA gene sequencing). Twenty-eight participants (55+ years) were recruited. Each randomized treatment arm lasted for 8 weeks with a 4-week washout period. Cognition, blood pressure, and urine samples were measured at each visit (5 total) while blood and fecal samples were collected at baseline, 8 weeks, and 20 weeks. Repeated-measures ANOVA was used to analyze the data. Across the treatments, no significant difference was observed for the different domains of cognition, blood pressure, or anti-inflammatory biomarkers. No intervention effect was found for genera or class of gut microbes. Low anthocyanin nectar derived from the QGP did not have any significant effects on cognition, blood pressure, or gut microbiota in healthy older adults.

Nutritional Value and Antimicrobial Activity of Pittosporum angustifolium (Gumby Gumby), an Australian Indigenous Plant.

The indigenous endemic plant P. angustifolium has received attention for nutraceutical and therapeutic applications in Australia. This study investigates for the first time the nutritional value (macro- and micronutrients, minerals, trace elements, polyphenols, carotenoids, saponins and antioxidant capacity) and antimicrobial activity of different botanical parts of P. angustifolium, either collected from the wild or cultivated. Different botanical tissues, geographic location and growing condition (wild vs. cultivated) showed significant (p < 0.05) effects on the tested bioactive compounds, with the leaves having significantly (p < 0.05) higher levels than the stems. Saponins and polyphenols could be identified as the main bioactive compounds in the leaves with up to 4% per dry weight. The extracts of P. angustifolium leaves and stems showed strong antioxidant and antimicrobial activities, especially against Candida albicans. These activities correlated (R2 = 0.64-0.92; p < 0.05) with the levels of polyphenols and saponins, indicating their biologic potential. Findings from this study may provide information for future applications of P. angustifolium in the functional ingredient or nutraceutical industry.

A dataset for anthocyanin analysis in purple-pericarp sweetcorn kernels by LC-DAD-MS.

This dataset refers to the accompanying article "Optimization of extraction procedure and development of LC-DAD-MS methodology for anthocyanin analysis in anthocyanin-pigmented corn kernels", published in Food Chemistry [1]. Here, we present concentrations, profiles, MS2 spectra of individual anthocyanins (including isomers of cyanidin-3-(6''-malonylglucoside)) of purple-pericarp sweetcorn (PPS) kernels. Furthermore, an additional mass spectrum of an artefact-anthocyanin produced in acidified extraction solutions were reported. This data is further discussed in the accompanying research article [1]. Delphinidin-3-glucoside was used as an internal standard to compensate for individual anthocyanin losses during extraction with acidified solutions. The generated data could be used for anthocyanin identification and quantification in different anthocyanin-containing plant matrices.

Bilirubin and related tetrapyrroles inhibit food-borne mutagenesis: a mechanism for antigenotoxic action against a model epoxide.

Bilirubin exhibits antioxidant and antimutagenic effects in vitro. Additional tetrapyrroles that are naturally abundant were tested for antigenotoxicity in Salmonella. Un-/conjugated bilirubin (1 and 2), biliverdin (4), bilirubin and biliverdin dimethyl esters (3 and 5), stercobilin (6), urobilin (7), and protoporphyrin (8) were evaluated at physiological concentrations (0.01-2 µmol/plate; 3.5-714 µM) against the metabolically activated food-borne mutagens aflatoxin B1 (9) and 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (10). Compound 8 most effectively inhibited the mutagenic effects of 9 in strain TA102 and 10 in TA98. Compound 7 inhibited 9-induced mutagenesis in strain TA98 most effectively, while 1 and 4 were promutagenic in this strain. This is likely due to their competition with mutagens for phase-II detoxification. Mechanistic investigations into antimutagenesis demonstrate that tetrapyrroles react efficiently with a model epoxide of 9, styrene epoxide (11), to form covalent adducts. This reaction is significantly faster than that of 11 with guanine. Hence, the evaluated tetrapyrroles inhibited genotoxicity induced by poly-/heterocyclic amines found in foods, and novel evidence obtained in the present investigation suggests this may occur via chemical scavenging of genotoxic metabolites of the mutagens investigated. This may have important ramifications for maintaining health, especially with regard to cancer prevention.