Sarah C Morrison

Plant and Food Research · Food Innovation - Food & Health Information

Consumption of polyphenols and dietary fiber as part of a normal diet is beneficial to human health. In this study, we examined whether different amounts of dietary soluble fiber (pectin) affect the absorption and metabolism of polyphenols from blackcurrant and green tea in rats. After 28 days, the rats fed blackcurrant and green tea with pectin (4...

Brassicaceae is one of the few plant families with the ability to incorporate the essential trace element selenium (Se) into organic compounds, and the vegetables are claimed to have a number of human health benefits based on both Se and glucosinolate content. We investigated the effect of Se addition on the nutrient composition of broccoli, purple...

The aim of this study was to identify the effect of bread making on fructan and fructose concentration in white and wholemeal breads made from commercial wheat flours, in particular the effect of yeast. Fructans are fructose polymers found in wheat. Fructans and excess fructose (in excess of glucose) have been identified as FODMAPs (fermentable oli...

Fructans are found naturally in some foods and added to many others to increase their fibre content. While fructans have health benefits for the majority of people, because they are poorly absorbed in the small intestine they can cause gastrointestinal side effects in 15–20% of the population. Researchers at Monash University (Melbourne) have ident...

Sweetpotato (Ipomoea batatas (L.) Lam.) is an important food crop and while commercial cultivars are traditionally yellow- or orange-fleshed, purple anthocyanin-rich variants have been selected within breeding programmes. The colour and putative health benefits of anthocyanins give them potential to become health supplements or natural additives in...

Both absorption and metabolism of quercetin and luteolin glycosides were observed. The presence of conjugated derivatives of quercetin and luteolin in the plasma and urine of these rats indicates that deglycosylation (usually in the small intestine) and extensive conjugation (primarily in the liver and small intestine) have occurred. Further deconj...

Berry fruit and green tea are each considered to be healthy foods due to their polyphenol contents. Their health benefit comes from the ability of polyphenols to reduce oxidative damage. Flavanoids are the most common polyphenols in the human diet and are found in fruit, vegetables, grains and beverages. These compounds show high antioxidant activi...

The absorption and metabolism of phenolic compounds (namely quercetin, luteolin and cyanidin glycosides) from a single meal containing a red lettuce extract was determined in rats over a 48-h period. Plasma, urine and faeces were collected at nine timepoints and analysed for flavonoid metabolites by LC-MS n. Several isomers of a mixture of methyl,...

Flavonoids, such as anthocyanins, are known antioxidants in vitro. Their presence in many fruits and vegetables has prompted researchers to validate epidemiological links between a diet rich in fruit and vegetables and the reduced risk of many diseases of aging. However, some vegetable brassicas, such as caulifl ower, are low in anthocyanins. In an...

Phytochemical bioavailability varies markedly with processing (not only between phytochemical class but within). When manufacturing a functional food, one may wish to consider 1) the impact of the processing technique on both beneficial phytochemicals and ANFs, 2) producing functional ingredients in order to optimise bioavailability of a single or...

Trypsin inhibitor activity (TIA) of 17 spring-sown field pea cultivars grown in New Zealand ranged from 0.33 to 0.75 TIU/mg DM. These values were much lower than those reported for most European pea cultivars. After soaking and cooking, values fell by 42–91%, with an average reduction of 78% (0.07–0.19 TIU/mg DM). After heat treatment, the residual...

Flavonoids, such as anthocyanins, are known antioxidants in vitro. Their presence in many fruits and vegetables has prompted researchers to validate epidemiological links between a diet rich in fruit and vegetables and the reduced risk of many diseases of aging. However, some vegetable brassicas, such as caulifl ower, are low in anthocyanins. In an...

The basic helix-loop-helix (bHLH) regulatory gene, Leaf colour (Lc), from maize is known to upregulate flavonoid biosynthesis when ectopically expressed in some Solanaceous species. Using Agrobacterium-mediated transformation we have transferred the Lc cDNA, under transcriptional control of the constitutive CaMV 35S promoter, into a wide range of p...

In vitro antioxidant tests can be useful indicators of possible health benefi ts. We demonstrated that red lettuces, often used simply as a food garnish, are potentially an excellent source of dietary antioxidants. Lollo rosso contained higher levels of phenolics than its green counterpart. The additional anthocyanins contributed to its signifi can...

In solution, acylated anthocyanin derivatives are generally more stable than non-acylated ones. However, not only do the type, number and position of the acyl group(s) on the sugar molecule all play a role in stability, but so do the structure and/or relative position of the aglycone and the sugar (Mazza & Miniati 1993). Further research will asses...

Cereal Chem. 83(1):57–61 Fourteen millstream flours, a straight-run flour, bran, pollard, and germ were prepared separately from two Australian and two New Zealand wheat cultivars using a 650 kg/hr pilot roller mill. Glutathione (GSH) and oxidized glutathione (GSSG) were measured in all samples. The Aus-tralian cultivars had higher levels of GSH an...

Determining the bioavailability of flavonoids will help to clarify their potential functions in vivo (e.g. as antioxidants). The physiological significance of dietary flavonoids depends on the extent of their absorption, distribution, metabolism, subsequent interaction with target tissues, elimination, and activity of their circulating metabolites....

The aims of this study were to determine the protein quality and trypsin inhibitor level for five cultivars of white field peas (`Rex', `Eiffel', `Bohatyr', `CFR/384', `Austin') as compared with a single cultivar of marrowfat pea (`Midichi'), and to determine the effects of heat treatment on these factors. Protein quality was determined using the p...

Cumulating evidence (anecdotal, epidemiological, dietary intervention studies) indicates that antioxidant phytochemicals in fruits, vegetables and other plant foods may lower the risk of chronic diseases associated with free radical damage. Heightened consumer awareness of, and demand for, antioxidant-rich foods has fuelled the need for scientific...

Sweetpotato (Ipomoea batatas (L.) Lam.) is thought to have originated from Central America. Known as 'kumara', sweetpotato was traditionally eaten by the Maori people of New Zealand and is commonly consumed in New Zealand today. Globally, sweetpotato is currently ranked as the tenth most important food crop, based on production. Commercial cultivar...

Lettuce originated in the Mediterranean basin, where it was used as a food in Egyptian times, and cultivated as a crop by the ancient Greeks and Romans for culinary and medicinal purposes. Today's consumers have the choice of many different varieties of leaf shapes and colours other than green, which are conveniently pre-packaged and available year...

Determining the bioavailability of flavonoids will help to clarify their potential function as antioxidants in vivo. Bioavailability is defined here as the proportion of an ingested nutrient that is available to the body for use in normal physiological functions. Thus, the physiological significance of dietary flavonoids depends on the extent of th...

14C-Quercetin-4'-O-b-D-glucoside was synthesised by our collaborators at the University of Glasgow, Scotland, UK (Caldwell et al., 2000). Thirty-two male Sprague Dawley rats (ca. 170 g) were fed a single experimental meal (0 h) containing 14C-quercetin-4'-O-b-D-glucoside (0.05%, 1 mg) in a lactic casein powdered diet. Rats were fed ad libitum a lac...

It is well known that berry fruit have certain health benefits and folkloric usage is documented. Scientifically, blackcurrants have long been regarded as having considerable health benefits, due to their high levels of vitamin C. Other health benefits include antioxidant activity. Blackcurrants have exceptionally strong antioxidant activity in vit...

There is strong epidemiological evidence that increased consumption of plant-based foods offers protection against some common diseases of aging, such as cardiovascular events, cancer, and age-related macular degeneration. These protective effects are thought to be due, in part, to antioxidants and their action against cellular oxidation reactions,...

Seventeen New Zealand grown, spring and winter pea cultivars were assayed for trypsin inhibitor activity, tannin and protein content. Trypsin isoinhibitors for ten of the cultivars were extracted using hydrochloric acid and purified by size exclusion chromatography and anion exchange chromatography. Isoelectric points and molecular masses were dete...

Oxalic acid and its salts occur as end products of metabolism in a number of plant tissues. When these plants are eaten they may have an adverse effect because oxalates bind calcium and other minerals. While oxalic acid is a normal end product of mammalian metabolism, the consumption of additional oxalic acid may cause stone formation in the urinar...

There are five classifications of field peas in NZ - blue, white, marrowfat, maple and forage peas. Each has a different use in food and fees production. Spring cultivars from each classification were assayed for trypsin inhibitor activity (TIA), tannin and protein content. TIA in NZ grown pea cultivars ranged from 0.33 to 0.75 TIU/mg sample. Tryps...