Studies on drying and storage of chilgoza (Pinus gerardiana) nuts
Present studies were undertaken with the aim of screening a suitable mode of drying and packaging material for storage of chilgoza nuts. A temperature of 55 °C was found most suitable for the drying of nuts in cabinet drier. Cabinet drier was found the best drying mode among four for drying of chilgoza nuts on the basis of quality characteristics such as moisture, water activity and sensory attributes. Further, out of five packaging materials selected in the study, glass jar followed by aluminium laminate pouch was found to be suitable for the packing and storage of dried nuts in ambient conditions for 6 months on the basis of retention of better physico-chemical and sensory attributes.
Effect of drying methods on nut quality of hazelnuts (Corylus avellana L.)
This study was conducted to determine the effects of hazelnut drying machine (DM1 and DM2; at 45 °C and 50 °C, respectively) and sun-drying (concrete ground and grass ground) methods on the chemical properties of Tombul, Palaz, and Ordu Levant hazelnuts. For this purpose, protein, lipid and moisture content, water activity, free fatty acid (FFA), peroxide value (PV), rancimat value (RV) and fatty acid composition were analyzed. As expected, it was observed that monounsaturated fatty acid (MUFA) was the main fatty acid group (81.58–84.80%) followed by polyunsaturated (PUFA; 9.53–11.42%) and saturated fatty acids (SFA; 5.87–6.92%), and the major group constituted ~ 99.00% of the total fatty acids, whereas the minor group constituted ~ 0.5% of these acids. However, caproic (C6: 0), caprylic (C8: 0), capric (C10: 0), lauric (C12: 0), eicosadienoic (20: 2), erucic (22: 1), docosadienoic (22: 2), and lignoceric (C24: 0) fatty acids were below limit of detection (< 0.001%). Samples dried in DM1 and DM2 had more MUFA (84.49%, 84.80, respectively), and lower SFA and PUFA than those using sun-drying methods. Following the drying process, the lowest FFA and PV (0.04–0.17%, 0.00–0.27 meq O2 kg−1, respectively) and the highest RV (5.46–6.05 h) were recorded in the DM1 method. Furthermore, it was also observed that as the heat increased (DM1 and DM2; 45–50 °C, respectively), oleic/linoleic acidity ratio, FFA, and PV increased and iodine value and RV decreased. Therefore, DM1 was thought to be a promising method for hazelnut drying.
CONVERSION OF LINOLEIC ACID HYDROPEROXIDE BY FRENCH BEAN HYDROPEROXIDE ISOMERASE
Hydroperoxide isomerase (HPI) was extracted from the cotolydon portion of sprouted French bean see & afer five days of incubation and partially purified by ammonium sulphate fractionation and ultracentrifugation. Linoleic acid hydroperoxides (LAHPO) were produced using commercial soybean lipoxygenase and purified using a silicic acid column and identijed by HPLC. The characterized LAHPOs were used as substrates for the French bean HPI. The purified French bean extract showed a three foid increase in activity over the crude preparation and a pH optimum of 7.2. Iheprimary end-products of the enzyme reaction were separated into ketol and carbonyl compounds and then further purified by preparative TLC. Subsequent GC-MS analysis of the ketolfraction indicated that HPI converted the 13-hydroperoxyoctadec-9, I1 dienoic acid primarily into 10,13-dihydroqoctadec-11 -enoicacid 0-ketol) and to a lesser extent into 12,13-dihydronyoctadec-9-enoic acid (a-ketol). Trace amounts of 9,12-dihydroxyoctadec-lO-enoic acid resulting from the isomerization of 9-hydroperoxyoctadec-10.12-dienoic acid were also found. Hexanal was revealed to be the principal carbonyl compound resulting from the decomposition of I3-hydroperonyoctadec-9,Il-dienoic acid, suggesting that a lyase was also present in the French bean extract.