Presence of Testa and Shell Maintains Oil Stability in Almond and Canarium Nuts

(1) Background: The oil stability of tree nuts during storage can be influenced by storage conditions such as temperature, humidity, and moisture concentration. However, few studies have assessed how the presence of testa and shell affects the oil stability of tree nuts during storage. We aimed to determine how storage conditions affect oil stability in almond and canarium, in particular, the presence of testa and storage time of nut-in-shell (NIS). (2) Methods: We measured peroxide value (PV), free fatty acid (FFA) and hexanal concentrations of almond and canarium (blanched vs. kernel-in-testa) stored at 45 °C for 24 days. We also measured PV, FFA and fatty acid composition of canarium samples at days 0 and 140 stored as NIS under ambient conditions. (3) Results: The presence of testa in almond and canarium decreased hexanal and PV concentrations at day 24 of incubation. Canarium PV and FFA concentrations increased over 140 days of storage in the shell compared to day 0. However, both PV and FFA concentrations remained within the acceptable threshold during storage. No changes in fatty acid composition were found during NIS storage. (4) Conclusions: Testa and shell could act as a natural coating, slowing down oxidation rates. Hence, long-term storage on nuts in testa or nuts in shell are recommended for tree nuts

Organic Matter Fractions Controlling Soil Water Repellency in Sandy Soils From the Doñana National Park (Southwestern Spain)

11 páginas.-- 5 figuras.-- 3 tablas.-- 102 referencias.-- Special Issue: Advances Towards an Integrated Assessment of Fire Effects on Soils, Vegetation and Geomorphological ProcessesThe relationship between soil organic matter (SOM) content and organic molecular assemblages (n-alkane/alkenes pairs and n-fatty acids) with soil water repellency (WR) in different sieve fractions (1–2, 0·25–1, 0·05–0·5 and  PA > PP > HH. A positive correlation was found between soil WR from each sieve fraction and SOM content. Most severe soil WR was detected in QS for all sieve fractions, followed by the finer fractions ( PA > HH. A significant correlation was observed between SOM content and the severity of soil WR in QS samples and finer fractions of soil under other vegetation (PA, PP and HH). Coarser fractions (1–2 mm) from PP, PA and HH 1–2 mm sieve fractions showed high severity of WR and relatively low SOM contents that could be explained by a low degree of evolution of the organic residues as seen by analytical pyrolysis, that is, higher alkane/alkene carbon preference index values and the presence of a higher diversity of fatty acid structures. CopyrightThis work has been partly funded by the Spanish Ministry for Economy and Competitiveness through projects HYDFIRE (CGL2010-21670-C02-01) and GEOFIRE (CGL2012-268 38655-C04-01). The firstauthor has been granted by a fellowship for Formation of Research Staff (BES-2013-062573) by the Spanish Ministry for Economy and Competitiveness.Peer reviewe

Effects of shade-tree species and spacing on soil and leaf nutrient concentrations in cocoa plantations at 8 years after establishment

Hosseini Bai, S ORCiD: 0000-0001-8646-6423Intercropping in agroforestry systems improves ecosystem services. Appropriate species compositions and spacing regimes are critical to achieve ecosystem benefits and improve yields of all the component crops. Cocoa (Theobroma cacao) is an important cash crop globally but it requires shade for survival and growth. However, the effects of shade-tree species composition and spacing regime on nutrient cycling in cocoa plantations are not well understood. This study investigated the effects of shade tree species and spacing regimes on soil and plant nutrient availability at 8 years after plantation establishment in Papua New Guinea. Three cocoa intercropping systems were established in which T. cacao was planted with either a non-legume timber tree, Canarium indicum, or a legume non-timber tree, Gliricidia sepium. The shade-tree spacing regimes included either 8 m × 16 m or 8 m × 8 m in the Theobroma + Canarium plantations. There was an ongoing thinning regime in the Theobroma + Gliricidia plantation, with a final shade-tree spacing of 12 m × 12 m. Soil total carbon (TC) and total nitrogen (TN) were significantly higher in the Theobroma + Gliricidia plantation with 12 m × 12 m spacing and the Theobroma + Canarium plantation with 8 m × 16 m spacing than in the Theobroma + Canarium plantation with 8 m × 8 m spacing. Foliar TN and P were correlated with soil TN and P, respectively, whereas no correlation was detected between soil and leaf K concentrations. Foliar TN, P and K were under ideal concentrations for T. cacao in all of the plantations. The Theobroma + Gliricidia plantation had higher soil water extractable phosphorus (P) than the two Theobroma + Canarium plantations, probably due to frequent pruning of the G. sepium trees. Foliar C isotope composition (δ13C) of T. cacao suggested that T. cacao close to G. sepium or close to C. indicum with spacing of 8 m × 16 m and 8 m × 8 m had similar light interception. However, increased C. indicum spacing increased the light interception of T. cacao trees that were not planted next to C. indicum. This study indicated that non-legume timber trees with an optimized spacing regime can be used as overstorey shade trees for T. cacao. However, our study indicated all three plantations required fertilisation and better nutrient management. © 2017 Elsevier B.V

Effects of roasting on kernel peroxide value, free fatty acid, fatty acid composition and crude protein content - Fig 2

<p>Peroxide values (A) and free fatty acid (FFA) (B) of the roasted <i>Canarium indicum</i> kernels at 110°C, 120°C and 150°C temperatures for 5 min (hatched column), 10 min (grey column) and 20 min (black column) compared to raw kernel (white column). FFA of the testa-off and testa-on kernels at 110°C (white and black columns, respectively) and at 120°C (grey and hatched columns, respectively) (C). Different lower case letters indicate significant differences at P<0.05.</p

Fatty acid composition (percentages) of <i>Canarium indicum</i> under different roasting regimes.

<p>Paired bold cases represent a significant difference at P<0.05.</p

<i>Canarium indicum</i> kernels (%) in each colour category and mottled colour category for different roasting regimes.

<p><i>Canarium indicum</i> kernels (%) in each colour category and mottled colour category for different roasting regimes.</p

<i>Canarium indicum</i>—Nut and removed pulp (A), testa-on kernels (B) and testa-off kernels (C).

<p><i>Canarium indicum</i>—Nut and removed pulp (A), testa-on kernels (B) and testa-off kernels (C).</p

Probability of two-way ANOVA for oil volume, moisture content, peroxide value (PV), free fatty acid (FFA), fatty acid composition, total saturated fatty acid (TSFA), total unsaturated fatty acid (TUSFA), oleic:linoleic ratio and protein content of <i>Canarium indicum</i> after roasting.

<p>Probability of two-way ANOVA for oil volume, moisture content, peroxide value (PV), free fatty acid (FFA), fatty acid composition, total saturated fatty acid (TSFA), total unsaturated fatty acid (TUSFA), oleic:linoleic ratio and protein content of <i>Canarium indicum</i> after roasting.</p