4. CROP AND NATURAL RESOURCE MANAGEMENT FOR SUSTAINABLE ENVIRONMENT
4.6 FOOD SCIENCE AND POST HARVEST TECHNOLOGY
Small-scale packaging machine for pulses
4.5.16 Cumin destalker
A cumin destalking machine was designed and developed. The unit is based on centrifugal principle and consists of two acrylic plates (30'') fixed horizontally. Top plate is fixed while lower plate rotates; provision has been made to adjust the clearance between the plates as per the length of cumin. As the cumin poses poor flow properties, a vibratory feeder is fitted with the unit for uniform uninterrupted feeding of cumin. The cumin fed between the plates at the centre experiences centrifugal force and tends to stand on its tips while it travels towards periphery. It is due to this action the stalk of cumin detaches.
Cumin Destalker
4.6 FOOD SCIENCE AND POST HARVEST
incidence of diseases or insect-pests the treated apple of pomegranates either with Surround or indigenously developed particle film (PCS-4) was non-significant.
4.6.2 Effect of pre-harvest fruit bagging on Kinnow mandarin fruits
The results revealed that bagging improved the fruit size of Kinnow (228.2 g) in comparison to non-bagged fruits. Further, bruising was also reduced by bagging (5.2%) over non-bagged fruits (46.6 %). Similarly, there was improvement in ascorbic acid content (22.2 mg100 g -1 pulp) and TSS (12 %) of the fruits over non-bagged fruits. Furthermore, the incidence of granulation (0.6%) was significantly reduced by pre-harvest fruit bagging.
Influence of pre-harvest fruit bagging on Kinnow mandarin
Attribute Bagged Non-bagged
Fruit weight (g) 232.6 186.8 g
TSS (%) 12.6 10.2
Ascorbic acid content (mg/100g
pulp) 24.3 18.8
Bruised fruits (%) 4.2 44.4
Granulation (%) 0.8 5.8
4.6.3 Postharvest spray treatment of ethrel and gum arabic for enhancing shelf-life of banana
Physiologically mature green banana were dipped or sprayed with ethrel @ 2000 ppm and gum acacia @
2% either alone or in combination. Treated fruits were kept at room temperature (25 ± 20C and RH 62% ± 2) for ripening. Combined application of gum acacia and ethrel spray given the best results over dipping among all the applied treatment. The spray treated (ethrel +gum acacia) fruits shown higher shelf-life (4 days), lesser occurrence of finger drop and anthracnose over dipping treatment during 10 days of storage.
4.6.4 Standardization of protocol for osmotic dehydration of apricot
Dehydrated apricots are high calorific products and considered rich in vitamins and minerals. Accordingly, six cultivars of apricot viz. CITH-1, CITH-2, CITH- 3, Gold Cot, Roxana and Shakarpara were evaluated for dehydration suitability. Osmotic dehydration of fruits consisting of dipping in prepared fruits in 70°
Brix sucrose syrup containing 2,000 ppm potassium metabisulphite (KMS) for 24 h followed by cabinet air drying (55 °C) to desired moisture (20±0.5 %) gave better dried product with good colour and appeal. Dried whole or halved fruits after removal of stones were preferred over whole fruits with stones in respect to appearance, texture and overall acceptability. Among different cultivars of apricot; cv. Roxana followed by CITH-2 were found better with respect to yield as well as quality of dried product.
4.6.5 Storage study of dehydrated spine gourd slices
To standardize the storage conditions for dehydrated spine gourd slices, were packed in three types of packaging material viz 200g LDPE (low density polyethylene) and HDPE (high density polyethylene) and 260 g ALPE (aluminium laminated polyethylene) pouches and stored at room temperature and low temperature for 6 months. Result revealed that samples packed in 260g ALPE pouches followed by storage at low temperature retain better nutritional quality in respect of ascorbic acid, antioxidant, total chlorophyll content, sensory score and least gain of moisture during storage followed by samples packed in 200g HDPE pouches stored at LT and RT during storage.
Anthracnose Finger drop
Control Treated
Brown spot
Combine effect of ethrel and gum Arabic spray treatment on incidence of anthracnose, brown spot and finger drop of banana
4.6.6 Influence of hexanal in extending postharvest storage life of apple
The influence of different concentrations of aqueous hexanal (0.01%, 0.02% and 0.03% v/v) as a dip treatment for 2, 3 and 4 min and also as vapour (120, 240 and 360 µl kg-1) for 2h and 4h was tested on apple fruit. Apple fruits given application of 0.01%
hexanal applied as dip treatment for 3 min soaking time retained higher firmness, reduced decay and improved the overall quality of the fruit upto 3 month storage under 1-2°C. Fumigation of freshly harvested fruit with hexanal vapour @ 360µL kg-1 for 2 h was also found to be an acceptable alternative to reduce decay and maintain overall fruit quality. Thus, post-harvest application of hexanal both as dip and vapour treatment holds promise in prolonging postharvest storage life and preserving quality of apple cv. ‘Royal Delicious’.
4.6.7 Infusion of micronutrients in the pre- cut cauliflower under vacuum
Minimally processed cauliflower cv. Pusa Sharad was infused with the micronutrient iron and the macronutrient calcium. Although imbibition in half cut florets was higher due to increased surface area, but the shelf life was limited, therefore, infusion studies were continued in whole florets. Iron solution on surface of cauliflowers got oxidized and resulted in slight discoloration. In case of infusion with calcium, pre-cut florets after exposing to vacuum for 15 minute .showed a 13 to 80% increase in the calcium content
as compared to control. Florets were shelf stable upto 10 days under 10°C. Thus, vacuum impregnation is a potential method to increase the nutritional value of the pre-cut vegetables.
4.6.8 Vacuum impregnation of citrus phenolics in ash gourd slices
Box-Behnken design successfully employed to optimize the vacuum impregnation (VI) in ash gourd slices. Different processing variables (blanching time, vacuum pressure and vacuum time) affected the infusion rate and thus the overall quality of the vegetable matrix. The kinetic model study revealed the correlation between all three variables and the mass transfer of phenolic compounds. VI process variables (blanching time (2.21 min); vacuum pressure (432.31 mbar) and time (28.18 min) prompted the maximum infusion of polyphenolic extract. Phenolics impregnation via VI could lead to nearly 300% increase in TPC of ash gourd. The model kinetic study using Fick's model, Fito and Chiralt’s model and Peleg constant revealed 450 mbar vacuum pressure exhibited higher effective diffusivity values (Deff) for TPC.
4.6.9 Spectrophotometric method to analyze acetic acid in fruit vinegar
Acetic acid was produced by Acetobacter strains in an Acetobacter medium supplemented with calcium carbonate and ‘C’ source. Acetic acid produced by Acetobacter aceti MTCC 2109 with glucose as substrate
Vinegar produced from fruit juice blends of phalsa and cantaloupe showing growth of Saccharomyces cerevisiae and Acetobacter aceti monitored during the process.
was 399 mg 100 ml-1, whereas Acetobacter aceti NRRL 2317 gave out 363 mg 100 ml-1 acetic acid with mannitol as substrate, in 4 days and 11 days, respectively. In the spectroscopic detection of organic acid (acetic acid), sample volume was reacted with acidified ethylene glycol to form an esterified product which was then converted into hydroxamic acid that developed colour in presence of ferric chloride (reagent). The coloured complex of hydroxamic acid was detected at UV Abs 200, in the concentration range of 1 mg to 10 mg acetic acid. The polynomial equation curve fit (2nd order equation y = -0.0077 x2 + 0.1356 x + 0.0079 with R² = 0.9886) was used for estimation.
Acetobacter aceti MTCC 2109 produced 3.017 % (equiv to 3168 mg%) acetic acid in 216 h, from fruit juice blend of phalsa and cantaloupe (60:40 ratio blend). The biomass growth of the two inoculates in the process of vinegar production was modelled using Gompertz equation. Saccharomyces cerevisiae helped in adding flavours to the final product. The maximal specific growth rate of Saccharomyces cerevisiae and A.aceti were 0.483 h-1 and 0.061 h-1, whereas their lag times were 22 h and 29 h respectively, in the fruit juice fermentation medium. Vinegar rich in anthocyanins (45 mg/L) was produced that had a total acidity of 4.98 % having a pH 3.19, yielding 89 % vinegar after decantation of cell mass and a good health drink.
4.6.10 Development of candied citrus peels from Kinnow mandarin
Shelf stable candied citrus peels were developed using peel (waste) of Kinnow mandarin. Blanching time, sugar concentration, infusion times were the three influencing process variables for standardization of the product. Blanching of pierced peel significantly helps in reducing the astringency of citrus peels. In the process of candied citrus peels development inverted sucrose acted as texturizing, preserving, sweetening, lustre agent. The RGB value of developed candied citrus peel was 250, 76, 6. A decrease in ‘L’ and ‘b’ value and increase in ‘a’ value in comparison with raw citrus peel showed an increase reddish and dark tinge of the developed candied citrus peel product.
Candied citrus peels of Kinnow mandarin
4.6.11 Formulation of lowfat gluten-free quinoa muffins
The sensory evaluation and textural studies revealed that incorporation of quinoa in muffins was acceptable upto 70% with no undue off-flavour or taste. In quinoa muffins, natural dietary fibre, psyllium husk was used as a fat replacer. Fat was replaced by psyllium husk at 20, 33 and 50% level of fat in the control muffins. It was possible to reduce fat from 22.45% in control muffins to 13.49% by incorporation of psyllium husk without any adverse effects on volume rise, texture and sensory attributes. Rather, acceptability of the muffins was further enhanced by using psyllium husk as fat replacer and source of dietary fibre.
Quinoa muffins
4.6.12 Formulation of quinoa-pearl millet baked snack
Gluten free baked snack with quinoa and pearl millet flours was formulated. The final formulation
contained 25% quinoa and 10% pearl millet flour along with rice and potato. The baked snack has 13.27% fat and 10.5% protein. The snack had 6.4 mg/ 100g iron, 2.85 mg 100 g-1 zinc and 453 mg 100 g-1 calcium. Shelf life studies of the snack upon packaging in metallized laminated packages have revealed its shelf life to be 4 months.
4.6.13 Development of roasted onion flakes
Three thermal methods viz. single pass tray drying, single pass microwave oven heating and a two stage heating including first tray drying followed by microwave oven drying were applied for development of roasted onion flakes. Heating in both single passes and two stage processes significantly influenced the textural and physic-chemical properties of onion flakes.
Two stage heating (1st stage heating in tray dryer at 60°C up to 30% moisture and 2nd stage heating in microwave oven up to 2-3% moisture) was found better in terms of improving crunchy texture and reducing time of heating. Pusa White Round and Pusa White Flat were found better for making crunchy onion flakes.