Protein quality and physico-functionality of Australian sweet lupin (Lupinus angustifolius cv. Gungurru) protein concentrates prepared by isoelectric precipitation or ultrafiltration

The protein quality and physico-functional properties of Australian sweet lupin protein concentrates, prepared by isoelectric precipitation or ultrafiltration, were assessed. The ultrafiltration process resulted in a higher yield of protein than did the isoelectric precipitation process. The lupin kernel and the two lupin protein concentrates had similar essential amino acid compositions that were inferior to ideal human requirements. True digestibilities of the isoelectrically precipitated (ISO) and the ultrafiltered (UF) lupin protein concentrates were similar but significantly higher (P<0.05) than that of casein. Net protein utilisations (NPU) of the ISO and UF protein concentrates were similar but significantly lower (P<0.05) than that of casein. The UF protein concentrate had higher protein solubility than did the ISO protein concentrate (P<0.05). Low foaming capacity, low viscosity, but high emulsification capacity (particularly at low pH) were observed for lupin protein concentrates.

Sensory acceptability of foods containing Australian sweet lupin (Lupinus angustifolius) flour

Foods containing Australian sweet lupin (Lupinus angustifolius) flour (ASLF) were assessed by consumer panelists (n= 54) in comparison to wheat flour (control) and defatted soy flour (DFSF) products. All ASLF products were rated in the acceptable half of the evaluation scale. General acceptability of ASLF chocolate chip cookies and breakfast bars was rated similarly to the control and DFSF variants (P > 0.05). ASLF pasta was rated lower than control but higher than DFSF pasta (P < 0.05), whereas ASLF addition reduced the general acceptability of muffins and bread (P < 0.05) compared with the other variants. Some ASLF products appeared palatable whereas ASLF incorporation rate in others requires reduction.

Capping the SRO's sweet tooth

The consequences of the State Revenue Office's (SRO) liking for fixtures and its liberal interpretation of the definition of chattels have been coming before the Supreme Court regularly.

Australian sweet lupin flour addition reduces the glycaemic index of a white bread breakfast without affecting palatability in healthy human volunteers

The addition of some legume ingredients to bread has been associated with effects on glycaemic, insulinaemic and satiety responses that may be beneficial in controlling type 2 diabetes, cardiovascular disease and obesity. However, the effect of Australian sweet lupin (Lupinus angustifolius) flour (ASLF) is unknown. This investigation examined the effect of adding ASLF to standard white bread on post-meal glycaemic, insulinaemic and satiety responses and palatability in healthy subjects. Using a randomised, single-blind, cross-over design, 11 subjects consumed one breakfast of ASLF bread and two of standard white bread ≥ 7 days apart after fasting overnight. Each breakfast also included margarine, jam, and tea with milk and contained 50g available carbohydrate. On each test day, blood samples were taken after fasting, then several times over 2 hours post-prandially, and analysed for plasma glucose and serum insulin. Subjects rated breakfast palatability and perception of satiety, in the fasting state and over 3 hours post-prandially, after which food intake from an ad libitum buffet and for the rest of the day was recorded. Incremental areas under the curves for glucose, insulin and satiety, glycaemic index, insulinaemic index and satiety index were calculated. ASLF addition to the breakfast reduced its glycaemic index (mean ± SEM; ASLF bread breakfast = 74.0 ± 9.6. Standard white bread breakfast = 100, P=0.022), raised its insulinaemic index (ASLF bread breakfast = 127.7 ± 12.0. Standard white bread breakfast = 100, P=0.046), but did not affect palatability, satiety or food intake. ASLF addition resulted in a palatable breakfast; however, the potential benefits of the lowered glycaemic index may be eclipsed by the increased insulinaemic index.

Water-binding capacity and viscosity of Australian sweet lupin kernel fibre under in vitro conditions simulating the human upper gastrointestinal tract

There is currently little understanding of the physicochemical properties in the human gastrointestinal tract of Australian sweet lupin (Lupinus angustifolius) kernel fibre (LKF), a novel food ingredient with potential for the fibre enrichment of foods such as baked goods. Since physicochemical properties of dietary fibres have been related to beneficial physiological effects in vitro, this study compared water-binding capacity and viscosity of LKF with that of other fibres currently used for fibre-enrichment of baked goods, under in vitro conditions simulating the human upper gastrointestinal tract. At between 8.47 and 11.07g water/g dry solids, LKF exhibited water-binding capacities that were significantly higher (P<0.05) than soy fibre, pea hull fibre, cellulose and wheat fibre at all of the simulated gastrointestinal stages examined. Similarly, viscosity of LKF was significantly higher (P<0.05) than that of the other fibres at all simulated gastrointestinal stages. The relatively high water-binding capacity and viscosity of LKF identified in this study suggests that this novel fibre ingredient may elicit different and possibly more beneficial physiological effects in the upper human gastrointestinal tract than the conventional fibre ingredients currently used in fibre-enriched baked goods manufacture. We are now performing human studies to investigate the effect of LKF in the diet on health-related gastrointestinal events.

Oral zinc sulfate solutions inhibit sweet taste perception

We investigated the ability of zinc sulfate (5, 25, 50 mM) to inhibit the sweetness of 12 chemically diverse sweeteners, which were all intensity matched to 300 mM sucrose [800 mM glucose, 475 mM fructose, 3.25 mM aspartame, 3.5 mM saccharin, 12 mM sodium cyclamate, 14 mM acesulfame-K, 1.04 M sorbitol, 0.629 mM sucralose, 0.375 mM neohesperidin dihydrochalcone (NHDC), 1.5 mM stevioside and 0.0163 mM thaumatin]. Zinc sulfate inhibited the sweetness of most compounds in a concentration dependent manner, peaking with 80% inhibition by 50 mM. Curiously, zinc sulfate never inhibited the sweetness of Na-cyclamate. This suggests that Na-cyclamate may access a sweet taste mechanism that is different from the other sweeteners, which were inhibited uniformly (except thaumatin) at every concentration of zinc sulfate. We hypothesize that this set of compounds either accesses a single receptor or multiple receptors that are inhibited equally by zinc sulfate at each concentration.

Australian sweet lupin kernal fibre : potential as a palatable functional food ingredient

These studies investigated whether lupin kernel fibre (LKF) could be formulated into palatable fibre-enriched foods demonstrating effects in humans of potential benefit to health. High-fibre baked goods of acceptable palatability were formulated using LKF and consumption of LKF resulted in potentially beneficial effects on satiety, insulin and cholesterol.

Sweet and sour preferences during childhood : role of early experiences

We investigated the effects of early experience on sweet and sour preferences in children. Eighty-three children were divided into four groups based on the type of formula fed during infancy and age. By using a forced-choice, sip-and-swallow procedure, we determined the level of sweetness and sourness preferred in juice. Children who were fed protein hydrolysate formulas, which have a distinctive sour and bitter taste and unpleasant odor, preferred higher levels of citric acid in juice when compared to older children who were fed similar formulas. No such difference was observed between the groups for sweet preference. However, the level of sweetness preferred in juice was related to the sugar content of the child's favorite cereal and whether the mother routinely added sugar to their foods. These data illustrate the wide variety of experiential factors that can influence flavor preferences during childhood.

Sweet preferences and sugar consumption of 4- and 5-year-old children : role of parents

We investigated the relationships in children between rules that restrict consumption of mono- and disaccharides (MDS), consumption of MDS and preferences for sucrose-containing orangeade. The background ideas of restriction rules we also investigated. To this end, 44 children (5.1 ^ 0.5 years) performed a rank-order and paired-comparison test of preference for five orangeades, which differed in sucrose concentration (0.14, 0.20, 0.29, 0.42, 0.61 M sucrose). Parents filled out a questionnaire concerning restriction rules and their children’s consumption of MDS-containing foods. Stronger restriction rules were related to a lower consumption of beverages that contained MDS and to a lower consumption of MDS-containing foods during breakfast and lunch. The most freedom to choose foods that contain MDS was given during the afternoon. Fifty-five percent of the children who were highly restricted showed a preference for the highest concentration of sucrose in orangeade. None of these children preferred the orangeade with the lowest concentration of sucrose. While 19% of the children who were little restricted preferred the beverage with the lowest concentration of sucrose, 33% preferred the beverage with the highest concentration. These parents generally believed that sugar has a bad effect on health and had similar background ideas concerning restriction
rules.

Australian sweet lupin kernal fractions as palatable functional food ingredients

Australian sweet lupin kernal fibre addition to foods in the diet beneficially modified serum lipids and the food products palatability was not reduced after repeated consumption. Australian sweet lupin kernal flour addition to white bread lowered the glycaemic index and did not reduce palatability, but increased the insulinaemic index.