Postharvest handling of ethylene with oxidative and absorptive means.

Fruit ripening is an unfolding of a series of genetically-programmed modifications and tend to be highly orchestrated irrevocable phenomenon mediated by ethylene. Phytohormone ethylene also leads to over-ripening, senescence, loss of texture, microbial attack, reduced post-harvest life and other associated problems during storage and transportation of fruits. Its harmful impacts on fresh fruits, vegetables, and ornamentals result in substantial product losses even up to 80%. Curbing of this inevitable menace is therefore need of the hour. Accrual of ethylene in packaging system should fundamentally be ducked to extend the shelf-life and uphold an adequate superiority of perishables in visual and organoleptic terms. The current review discusses about properties, factors affecting and impact of ethylene, intimidation of its impact at gene vis-à-vis activity level using gene-modification/inhibition techniques, chemical/physical in conjunction with other suitable approaches. It also entails the most commercially cultivated approaches worldwide viz. KMnO4-based oxidation together with adsorption-based scrubbing of ethylene in thorough details. Future ethylene removal strategies should focus on systematic evaluation of KMnO4-based scavenging, exploring the mechanism of adsorption, adsorbent(s) behavior in the presence of other gases and their partial pressures, volatiles, temperature, relative humidity, development of hydrophobic adsorbents to turn-up under high RH, regeneration of adsorbent by desorption, improvement in photocatalytic oxidation etc. and further improvements thereof. Supplementary Information: The online version contains supplementary material available at 10.1007/s13197-023-05777-1.

Development of composite mechanical peeler cum juice extractor for kinnow and sweet orange.

A mechanical peeler cum juice extractor was designed and developed for simultaneous peeling and juice extraction of kinnow and sweet orange fruits. Based on the designed components and prior optimization of operational parameters for peeling of both the fruits, a functional machine was developed. Major components of the machine include spur gear assembly (Φ 102 mm and Φ 76 mm), two fruit holders (Φ 30 mm), revolving shaft with length 570 mm, clearance of the tool for peeling 25 mm and cutting knife with length 80 mm, respectively. This peeler was operated using a motor, gear assembly and the combination of pulleys. The juice extractor was also fitted with a conical hopper having a flattened base to facilitate the juice extraction of peeled fruits. For performance evaluation, fruit rotation speed was considered as independent parameter and was varied at 220, 260, 280, 300, 360 rpm, whereas peeling time (s), peeling efficiency (%), peel remained on fruit (%) and juice loss (%) were taken as dependent parameters. The machine resulted in best performance at fruit rotational speed of 220 rpm (kinnow) and 260 rpm (sweet orange) with higher peeling efficiency and minimum juice loss. The capacity for peeling and juicing operation was 60-90 kg/h (kinnow) and 50-60 kg/h (sweet orange), respectively. This composite peeling cum juice extractor machine can find its applicability in cottage citrus fruit juice processing industries as well as for the domestic juice sellers.

Post-harvest processing and valorization of Kinnow mandarin (Citrus reticulate L.): A review.

Kinnow is a prevalent fruit crop of the mandarin group and belongs to the Rutaceae family. It is nutritionally rich in vitamin C, vitamin B, ß-carotene, calcium, phosphorous and other health beneficing compounds. The fruit is grown commercially for fresh consumption and since the processing techniques are less prominent, a plentiful amount of harvested fruit goes for waxing and grading operations. To reduce the post-harvest losses, appropriate processing techniques need to be followed as considerable fruit waste is generated while processing. The foremost fruit wastes viz. peel and seeds are rich source of bioactive compounds and can be utilized for the extraction of aromatic compounds, essential oils and low-methoxyl pectin. Overall utilization of kinnow and its components through various technological interventions will not only enhance the profitability of processing industries but also assist in reducing the pollution load on the environment. The prevailing bitterness in kinnow juice has constrained its processing, value-addition, popularity and acceptability. Limited work has been done on kinnow processing leaving scarce relevant literature published on the post-harvest management. Efforts made by researchers worldwide, regarding the post-harvest application of kinnow and its by-products for product development, value addition and waste utilization is presented and discussed in this paper. This compiled information is envisioned to encourage the cottage food processing units in order to improvise the overall benefits along with achieving complete utilization of kinnow.

Nullifying phosphatidic acid effect and controlling phospholipase D associated browning in litchi pericarp through combinatorial application of hexanal and inositol.

The role of phospholipid modification initiated by phospholipase D (PLD) in enzymatic browning has been revoked through this study. Various alcohols and aldehydes were tried to read out their PLD controlling behaviour. Based on in-vitro results, reagents like hexanal and inositol were used to regulate PLD activity of litchi fruit stored at ambient temperature and their effects on fruit quality and physiological characteristics were also investigated. The results showed that combinatorial chemical treatment was successful in maintaining freshness of fruit through delayed physiological loss in weight and hence maintaining firmness. Combinatorial treated fruit had lower browning index than control by day 7. This novel treatment also maintained comparable levels of total phenolics and lowered the level of malondialdehyde. Evaluation of antioxidative enzymatic profile also confirmed the alleviation of oxidative stress of litchi fruit at ambient temperature. Thus, this strategy of enzyme regulation could play a vital role in overall quality maintenance of litchi fruit.

Development of meat-bone separator for small scale fish processing.

The belt and drum type meat-bone separator was developed for small-scale fish processing and evaluated using Tilapia fish (Oreochromis mossambicus) in terms of capacity, yield, percentage yield, bone content, colour and power consumption. It consists of a perforated drum (3 mm), single phase electric motor, speed reduction gear box and drive system. The machine was evaluated using two food grade belt viz., natural rubber (Belt A-35 shore) and canvas belt (Belt B-65 shore) for three drum speeds. The machine capacity was in the range of 45.59 to 68.54 kg h(-1) for belt A with a yield of 1.148, 1.069 and 1.066 kg, and 49.13 to 78.13 kg h(-1) for belt B with a yield of 1.253, 1.312 and 1.269 kg at drum speeds of 14, 20 and 24 rpm, respectively. For belt A, the highest yield (1.148 kg) was obtained at 14 rpm drum speed which was 63.78% on dressed weight basis and for belt B, the highest yield (1.312 kg) was obtained at 20 rpm drum speed which was 72.89% on dressed weight basis. The increased number of passes for meat recovery increased the chances of insertion of bone fragments into minced meat and decreased the colour values (L-a-b). The total energy consumption did not vary significantly.