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 Mois ture and Packaging on the She l f L i fe o f Wheat F lour
Tempering of the wheat samples with d ifferent amounts of water was done to obtain f lour t rea tments having different moisture levels i .e . T1 (13.5%), T2 (13%), T3 (12%), T4 (11%), T5 (10%) and T6 (9%) af ter mil l ing. These treatments were separately packed in polypropylene and paper bags. During the s torage per iod of 60 days, each t reatment in both polypropylene and paper bags was evaluated for proximate composi t ion, insect infestat ion, mold growth and to tal i ron. The crude protein and crude fa t decreased with s torage per iod. Mois ture content (m.c) in T1 (13.5% m.c.) , T2 (13% m.c. ) and T3 (12% m.c.) decreased. Changes were minimum in T4 (11% m.c.) and increasing trend was seen in T5 (10% m.c.) and T6 (9% m.c.) . The changes were more in polypropylene than in paper bags. Changes in ash and f iber were non s ignif icant dur ing the s tudy. Insect infestat ion and mould growth were also favored by higher mois ture content of f lour . Paper packaging was found to be sui table against insect infestat ion and mould growth. Total i ron also showed a decreasing t rend with s torage per iod. Lower f lour mois ture (T6= 9%) and paper packaging were found to be sui table for s torage s tabi l i ty & longer shelf l i fe of wheat f lour . ______________________________________________________________ INTRODUCTION In Pakis tan, wheat is mainly mil led to whole wheat f lour for the product ion of unleavened f lat bread local ly known as “Chapat i” while rest is used for o ther bakery products l ike bread, b iscui ts , cakes, pastr ies , pizzas etc . The annual product ion of wheat in Pakistan is 19.23 mil l ion tones and the area covered is 8 .69 mil l ion hectares (Anon. 2003). Mois ture content of f lour is very important regarding i ts shelf l i fe , lower the f lour mois ture , the bet ter i ts s torage s tabi l i ty. The deter iorat ion of baking qual i ty is a lso less a t lower moisture content which can be credi ted to retarded respirat ion and act iv i ty of microorganisms (Staudt and Zeigler , 1973) Mois ture is an important factor in control l ing grain infestat ion. Insects that l ive on s tored grains and their products depend upon the mois ture supply. General ly , moisture content of 9% or lower restr ic ts infestat ion. Mois ture is a lso of great importance for the safe s torage of cereals and their products regarding microorganisms, par t icular ly cer tain species of fungi . At lower mois ture fungi wil l not grow but a t about 14% or s l ightly above, fungal growth takes p lace (Hoseney, 1994) . Higher l ipolyt ic and proteolyt ic act iv i t ies are related to h igher moisture content , which fur ther lead to loss in nutr ients (protein and fat) and product ion of more FFA resul t ing in infer ior sensory character is t ics . In modern age, food packaging has become very important because of protect ion of the product f rom contaminat ion by macro & microorganisms and their f i l th , prevent ion from loss or gain of moisture , shield ing the product f rom oxygen and to faci l i ta te handl ing (Bal l , 1960) . Good packaging actual ly serves two purposes, which are essent ia l ly technical and presentat ional . Technical aspects in packaging aim to extend the shelf l i fe of the food by bet ter protect ion from al l the hazards dur ing s torage. Presentat ional aspects are not concerned with shelf l i fe but such packaging increases sales by creat ing a
Investigations on the rôle of organic matter in plant nutrition
1. As the result of decomposition of green manure in a swamp soil, the coarse fractions (including coarse and fine sand) of the surface layer (first 3 inches) decreased by 11·2 per cent. while the fine ones (silt+clay) increased by 9·8 per cent. in the course of 43 days. The effect was less pronounced in the manured soil maintained at 60 per cent. saturation, while no alteration was to be noticed in the case of the unmanured specimens. 2. Treatment with dilute hydrochloric acid prior to dispersion had no appreciable effect on the estimates of mechanical composition obtained in the different cases. Loss in solution was also comparatively small. 3. The silica-sesquioxide ratio increased slightly as the result of decomposition of green manure in swamp soil. The composition of the fine fractions was also altered, the total percentages of the oxides of iron, aluminium and silicon increasing from 90·5 to 99·3 in the course of 71 days. 4. The practical significance of the above and related observations has been discussed.