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Macadamia Nuts (macadamia + nut)
Selected AbstractsDropping macadamia nuts-in-shell reduces kernel roasting qualityJOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 13 2010David A Walton Abstract BACKGROUND: Macadamia nuts (,nuts-in-shell') are subjected to many impacts from dropping during postharvest handling, resulting in damage to the raw kernel. The effect of dropping on roasted kernel quality is unknown. Macadamia nuts-in-shell were dropped in various combinations of moisture content, number of drops and receiving surface in three experiments. After dropping, samples from each treatment and undropped controls were dry oven-roasted for 20 min at 130 °C, and kernels were assessed for colour, mottled colour and surface damage. RESULTS: Dropping nuts-in-shell onto a bed of nuts-in-shell at 3% moisture content or 20% moisture content increased the percentage of dark roasted kernels. Kernels from nuts dropped first at 20%, then 10% moisture content, onto a metal plate had increased mottled colour. Dropping nuts-in-shell at 3% moisture content onto nuts-in-shell significantly increased surface damage. Similarly, surface damage increased for kernels dropped onto a metal plate at 20%, then at 10% moisture content. CONCLUSION: Postharvest dropping of macadamia nuts-in-shell causes concealed cellular damage to kernels, the effects not evident until roasting. This damage provides the reagents needed for non-enzymatic browning reactions. Improvements in handling, such as reducing the number of drops and improving handling equipment, will reduce cellular damage and after-roast darkening. Copyright © 2010 Society of Chemical Industry [source] Nutshells as granular activated carbons: physical, chemical and adsorptive properties,JOURNAL OF CHEMICAL TECHNOLOGY & BIOTECHNOLOGY, Issue 5 2001H Wartelle Abstract Nutshells from seven different sources (pistachio, hazelnut, almond, black walnut, English walnut, macadamia nut, pecan) were converted to granular activated carbons (GACs) by carbon dioxide activation. A portion of the GACs were oxidized with compressed air and the physical (yield, surface area, attrition), chemical (pH, surface charge) and adsorptive (organics uptake, metal ion uptake) properties of both oxidized and non-oxidized carbons were determined. Differences in uptake of organics, especially of polar compounds, were found between GACs made from almond shells, the group consisting of black walnut shells, English walnut shells and pecan shells, and macadamia nutshells. Oxidation had its greatest effects on pH, surface charge and uptake of metal ions. The changes due to oxidation were found to be independent of carbon source material. GACs with specific properties can be produced with judicious selection of carbon precursor and oxidative treatment. © 2001 Society of Chemical Industry [source] Compositional analysis and roasting behaviour of gevuina and macadamia nutsINTERNATIONAL JOURNAL OF FOOD SCIENCE & TECHNOLOGY, Issue 1 2010John Birch Summary This study compares the composition of macadamia and gevuina nuts following natural abscission and air-drying of intact nuts and compares chemical and sensory properties on roasting gevuina nuts using a reported macadamia roasting process. The markedly higher fat content of macadamia (75% vs. 43%) reflected a higher percentage of protein, moisture, ash and carbohydrate in gevuina nuts. Gevuina nuts also had lower energy and pH values than macadamia. Water activities were similar. Both oils were around 80% monounsaturated, but differed widely in positional isomerism. On roasting, macadamia nuts developed sweet, nutty, buttery notes along with brown colour development (measured using L*, a*, b* values) after 20 min at 135 °C while gevuina nut colour and aroma took at least 30 min, where the aroma was more hazelnut-like. Extractable volatiles were significantly higher for macadamias following roasting. [source] | ||||||||||