Preserving Celery Quality: Organic Cultivation and Room Temperature Storage with LDPE Wrapping Yields Optimal Results

. Periodic use of chemical pesticides in conventional farming systems can lead to environmental degradation. Organic product are believed to be potential for human health. This research was conducted for 144 hours to determine the eﬀect of cultivation and storage methods on the chemical-physical, and organoleptic characteristics of celery during the post-harvest period. This study used a Factorial Randomized Block Design which was repeated three times with the ﬁrst factor is the cultivation method which consisted of two levels, namely, organic and conventional. The second factor was the storage method which consisted of four levels, namely, stored in the refrigerator with wrapped in LDPE Bag, stored in the refrigerator without wrapping in LDPE Bag, stored in a room temperature wrapping in LDPE bag, and stored in a room temperature without wrapping in LDPE bag. Data obtained were analysed by analysis of variance and then continued with the 5% HSD Test. The results of weight loss showed that the best treatment was obtained in organic cultivation with the scores 48.03% and stored in the room temperature with LDPE bags with the scores 18,31%, and the organoleptic scores were colour 4.13, and freshness value 4.17.


Introduction
Celery (Apium graveolens L) is a plant of the Apiaceae family, and is one of the annual or perennial plants that grows throughout Europe and tropical and subtropical regions of Africa and Asia, especially Indonesia.Nutritional and other characteristics of a product depend on environmental factors and cultivation practices.Vegetables grown in organic farming systems believed have greater potential in improving quality and nutrition [1].While conventional cultivation systems are usually based on pesticide inputs and high levels of chemical fertilizer which might increase environmental pollution and reduce food safety of a product [2], and potentially affected plant physiology in the final phase of vegetative growth.
Low food quality not only related to low in nutrition, quality, and shelf life, but also largely determined on cultivation practices.In addition, post-harvest handling processes can also result in deterioration in foodstuffs grade and quality, apart from physiological, mechanical, and microbiological damage [3].To maintain product quality so that it remains durable after harvest, the metabolic process must be suppressed as low as possible by storage and packaging [4].
Therefore, this study was conducted to determine the effect of cultivation and post-harvest storage methods on the characteristics of celery especially on weight loss, and organoleptic characteristics.

Material and postharvest experiment
Celery vegetables from two locations with different cultivation methods.Celery from organic cultivation were taken from vegetables farm at Seloliman Village in district of Ngoro, and conventional one were taken from Sajen village in district of Ngoro.Both of them located in the same regency, Mojokerto in East Java Province.Harvesting process was carried out in the morning with the aim of obtaining greatest moisture of this kind of vegetable.Harvested celery were then placed on plastic bags of LDPE of 0.4 mm thickness and 40 cm x 35 cm in size to save their moisture.. Fresh harvested celery then transported to Food Technology Laboratory in Sidoarjo on the same day.Fresh celery then weighed approximately about 30 g each samples and treated with postharvest treatments.Treatment applied in this experiment were packaging and storage temperatures.Packaging consisted of two levels those were packaging with plastic bags and without packaging, whereas storage temperatures consisted also of two levels, those were room or ambient temperature which was 29 -30℃ in average and refrigerator temperature which was average on 4℃.Then samples were stored for 144 hours on each storage treatments.
Observation were conducted on initial storage and every 24 hours until 144 hours to find out the value of weight loss from celery, and organoleptic characteristics were consisting of: color, and freshness value of celery by utilizing 30 panellists with an assessment score range from lowest to highest were 1, 2, 3, 4, and 5 in scoring test.

Experimental design and data analysis
Randomized Complete Block Design (RCBD) arranged in factorial was used in this experiment.The first factor was cultivation methods (S) consisted of two levels, those were conventional and organic.The second factor was postharvest storage methods (P) which consisted of four levels, those were, stored in the refrigerator and wrapped with LDPE Bag; stored in the refrigerator without wrapping in LDPE Bag; stored in a room temperature and wrapped with LDPE bag, and stored in a room temperature without wrapping with LDPE bag.
Data obtained were analysed by analysis of variance then followed by the 5% Honest Significant Difference (HSD) test.

Weight loss
There were no interaction between cultivation methods and storage methods on weight loss after 144 hours.Table 1.shows that the treatment of organic cultivation methods is not significantly different from conventional cultivation methods (P >0,05), but on the treatment of the storage methods shows a significally different (P < 0,05).1. Shows that there were no interaction between cultivation system and storage methods for weight loss.Weight loss is not affected by the cultivation systems, but from the activity of respiration, transpiration and the activity of bacteria.Generally, weight loss is attributed to water loss, and transpiration is the most important cause of deterioration in post-harvest vegetables [5].Therefore, storage methods significantly affected weight loss after storage since 24 hours until 144 days.Weight loss were higher day by day observations and tend to be higher at room temperature without wrapping with LDPE bags.This fact is caused by a higher storage temperature induced higher moisture loss due to higher evaporation [7].In addition, weight loss also affected by plastic wrap that shown by lower weight loss occurred on celery stored in a plastic bags wrap.Weight loss is one component that affected by storage temperature, higher temperature may resulted in higher respiration rate.Wrapping in LDPE plastic bags effected percentage of weight loss of vegetables.The use of polypropylene (PP) plastic packaging materials affected the percentage of weight loss and discoloration of tomatoes.The use of polypropylene (PP) plastics is effective in reducing the percentage of weight loss.

Organoleptic characters
The average results of organoleptic observations consisting of colour, aroma, texture, and degree of freshness to celery leaves after both 24 and 72 hours of storage are shown in Table 2. Numbers followed by the same letter in the same column show no significant difference based on 5% HSD test Table 2 shows that highest colour and freshness value are achieved by celery which were cultivated in organic system both on 24 and 72 hours after stored in refrigerator and wrapped by plastic bag.This result was in line with research of broccoli which were stayed green and fresh during storage in cold temperature and wrapped in plastic bags [9].The longer the vegetables were stored, the lower the colour and the freshness value.
Freshness value of celery also decreased at 72 hours after storage compared to after 24 hours of storage.Celery a decrease in the favourability of the level of freshness due to the transpiration process that is so fast that it causes wilting [10].The rate of freshness in horticultural products is prone to decrease due to higher weight shrinkage [11].

Conclusion
There were no interactions between cultivation systems and storage methods on weight loss during 144 hours of storage.Weight loss is not affected by cultivation system.By storing celery in plastic bags whether in refrigerator or room temperature may reducing weight loss..Both highest colour and freshness value of organoleptic characters of celery on 24 and 72 hours storing achieved by organic celery which wrapped in plastic bags whether stored in refrigerator or room temperature.

Tabel 1 .
Weight loss (%) of celery after 144 hours postharvest period on cultivation system and storage methods

Table 2 .
Organoleptic characters of celery after 24 and 72 hours of storage