Advances in Agricultural Science 06 (2018), 03: 49-60
Optimization of Ethylene inhibitor-mediated controlled ripening of tomato (Solanum lycopersicum L.)
Sajib Barua 1, Tahsin Rahi 1, Oindrila Hossain 1, Antara Mazumder 1, Rabeya Sharmin 1, Tasnim Zaman 1, Durjoy Ghosh 1 and Shoeb Ahmed 1*
1 Department of Chemical Engineering, Bangladesh University of Engineering and Technology, Dhaka- 1000, Bangladesh.
Green tomatoes (Solanum lycopersicum L.) were treated with water, Salicylic Acid (1.5 mM SA), 1-Methylcyclopropene (1400 µg/L 1-MCP), Ethanol (15 % w/w), Gibberellic Acid (10-4 M GA) and Maleic Acid (100 mg/L MA). 1-MCP, GA and Ethanol inhibited the ripening process of the tomatoes and the food quality was also retained. However, SA and MA failed to delay the ripening process of the tomatoes. The most effective treatment was 1-MCP in delaying ripening, therefore, further experiments were performed to find the optimum dosage of 1-MCP. Tomatoes treated with 200, 500 and 800 µg/L of 1-MCP delayed ripening of tomato by 11, 18 and 20 days, respectively, however, the food quality was affected slightly at higher 1-MCP concentration. 500 µg/L solution of 1-MCP delayed the ripening process of the tomatoes without changing the food quality significantly. This indicates that 1-MCP application (500 µg/L solution) can be used effectively to extend the storage life up to 18 days without any adverse effect on the quality of ripe tomato and can be adopted commercially to increase the shelf life in semi-ripen stage longer time at room temperature.
How to Cite: Barua, S., Rahi, T., Hossain, O., Mazumder, A., Sharmin, R., Zaman, T., Ghosh, D., & Ahmed, S. (2018). Optimization of Ethylene inhibitor-mediated controlled ripening of tomato (Solanum lycopersicum L.). Advances in Agricultural Science, 6(3), 49-60.
Tomato is regarded as one of the most extensively grown and consumed climacteric vegetables all over the world. It is constituted of dietary ﬁbers, vitamins, minerals, carotenoids, ﬂavonoids and phenolics. It is also considered a good source of antioxidants, vitamin-C. Significant amount of tomatoes get over-ripen or rotten before consumption in developing and less developed countries because of the large volume of production and lack of proper post-harvest management (Kader, 2005; Kitinoja et al., 2011). Ethylene is a natural plant growth hormone. It has regulatory role in ripening process of fruits and vegetables (Bapat et al., 2010; Barry and Giovannoni, 2007; Huber, 2008). Some chemicals known as ethylene inhibitors, were found to reduce ethylene induced effects on fruits and vegetables and thus delay the natural ripening process to eventually increase the shelf life (Barua et al., 2015; Grichko et al., 2006; Osorio et al., 2013). 1-Methylcyclopropene (1-MCP) has been suggested as one of the possible agents that could increase the shelf life of vegetables (Mir et al., 2004; Su and Gubler, 2012). However, the efficiency of 1-MCP in delaying ripening of tomato depends on concentration of 1-MCP (Moretti et al., 2002). This advocates the importance of proper optimization of 1-MCP dosage for effective and economical means of increasing shelf life. Salicylic acid (SA) is an abundant plant phenolic compound that regulates a number of processes in plants and it is an important component in the signal transduction pathway (Raskin, 1992). It was found to work as ethylene inhibitor for various fruits and vegetables (Bal and Celik, 2010; Lolaei et al., 2012). Ethanol was also found to delay ripening of various fruits like avocado, tomato and banana (Turner and Fortescue, 2012). It was reported that Gibberellic acid (GA) delayed the anthocyanin synthesis and chlorophylls degradation (Martinez et al., 1994). Post-harvest treatment of GA was reported to delay ripening process and also to increase the quality of different climacteric fruits (Kandungan et al., 2013).
Food quality is a combination of intrinsic and extrinsic attributes where texture, sweetness, acidity, aroma, flavor and nutritional value like TSS (Total Soluble Solids), TA (Titrable Acidity) and Vitamins are internal attributes, and shape, peel color and free from defects are the external attributes (Costa et al., 2000). TSS content generally increases with the stage of ripening and thus it is considered as a useful index of the ripening stages of fruits and vegetables (Iqbal et al., 2012). TSS content also contributes to the food quality, aroma and taste (Hernandezmunoz et al., 2008). With the commencement of ripening, the amount of starch starts to decrease. TA and pH are important components of organoleptic quality of fruits and vegetables (Bugaud et al., 2011). They affect not only the sour taste but also the sweetness of fruits and vegetables (Lyon et al., 1993). Acidity is due to the presence of organic acids (malic and citric acids mainly) (Baldwin, 1993). TSS and TA are considered as the key characteristics determining the taste, texture and feel of fruit segments. Fruit sweetness and acidity are contributed by TSS and TA, and thus they give fruits their characteristic flavor and quality (Malundo et al., 2001). Lower pH value, caused by higher concentration of organic acids, significantly alters the environment for pathogenic growth and thus reduces the post-harvest loss. The rise in pH and decrease in TA indicates that acid concentrations in the fruit are declining with maturity (Anthon et al., 2011).
Ripening of fleshy vegetables like tomato is associated with changes of color and flavor factors such as soluble solids concentration, acidity and aroma (Watkins, 2008). Controlled ripening of tomato can be very useful in increasing shelf life lead to reduced food spoilage reduction. Therefore, the most suitable ethylene inhibitor that could compromises between delayed ripening of tomato and alternation of food quality, needs to be identified. Several studies have been conducted on this and these results may vary according to the geographical location, climate and types of tomato. The main objective of this study is to investigate the impact of different ethylene inhibitors and their dosage on post-harvest ripening, food quality and storage life of green mature tomato by measuring several food quality indicators at this subcontinent climate.
Materials and methods
Locally grown (BARI-10) fresh, green tomatoes (Solanumlycopersicum L.) were purchased from a local market and were used for each set of experiments. Tomatoes were sorted based on uniformity of size eliminating the damaged tomatoes and to obtain the samples of uniform ripeness of color stage-1 according to the standard tomato ripening color chart (Figure 1a).
Evaluation of different anti-ethylene agents
During each experiment, six groups of tomatoes (six tomatoes in each group) were treated with water (Control), 1.5 mM salicylic acid, 1400 µg/L 1-Methylcyclopropene, 15 % (w/w) ethanol, 10-4 M gibberellic acid, and 100 mg/L maleic acid. Tomatoes were washed well with deionized water and dipped into 5L anti-ethylene solutions at 22ºC for 5 hr. Following the treatment, tomatoes were air dried and stored at 20±4 ºC and 70±5 % RH.
Optimizing the doses of anti-ethylene agents
Thirty tomatoes were divided into 5 groups and were washed well followed by the treatment with different concentrations of aqueous 1-MCP (0.1% active ingredient, AgroFresh, Inc., Rohm and Haas, Philadelphia). In this experiment, 0, 200, 500, 800 and 1100 µg/L of 1-MCP were applied on tomatoes for 5 h at 22ºC by dissolving 1-MCP granules containing the desired levels of active ingredient into distilled water in 5 L plastic buckets. Tomatoes were treated and stored like earlier experiment.
Assessments of the ripening parameters of tomato
Each tomato was weighed at the end of treatment period (air dried first) and also on different days till the full ripen stage (color stage 6). Weight loss is intended as the percentage loss of the initial weight and the standard tomato ripening color chart was used to identify the change in the skin color (Fig-1a). Tomatoes with complete conversion of skin color into red (color stage 6) are considered as totally ripen according to the color chart. The ripened tomatoes were homogenized in a grinder and 10 g of ground tomato flesh was resuspended in 100 mL of distilled water for further analysis. It was filtered through Whatman filter paper No. 2. The pH and titrable acidity (TA) of the filtrates were evaluated using a pH meter (pH-526; WTW Measurement Systems, Germany) and adjusted to pH 8.1 using freshly prepared 0.1N NaOH solution (Ranganna, 1986). TA was expressed as g citric acid per 100 g of tomato flesh weight (%). By means of a hand-held Kruss refractometer (Model HR 900, Germany) the total soluble solids (TSS) was assessed at 22 ºC and expressed as a percentage. Ascorbic acid (Vitamin C) content was measured by titration (Sowa and Kondo, 2003) and results were expressed in mg ascorbic acid per 100 g of tomato flesh weight. All the measurements are average of measurements on four different samples.
Results and Discussion
Evaluation of different anti-ethylene agents
The post-harvest storage temperature and relative humidity are the two main parameters that control the metabolism rate of tomato. The rate of weight loss with storage time showed no significant differences among the tomatoes treated with GA, MA, Ethanol and 1-MCP, however, the weight loss trend was substantially slower compared to the control (Figure 1b). At the fully ripen stage of MA treated tomato, the weight loss of MA treated tomato was 3.71% (14th day) which was higher than that of other treated tomato on that day. The weight loss at the fully ripen stage was 4.19% for ethanol treated tomatoes (17th day) whereas 3.05% for GA treated tomatoes (21st day) and 3.32% for 1-MCP treated tomatoes (25th day). Weight loss of Control (9.89% on 12th day) and SA (5.11% on 9th day) treated tomatoes were slightly higher compared to other chemical treated tomatoes. Although, GA, MA, Ethanol and 1-MCP treated tomatoes showed decrease in weight loss, lowest weight loss was observed for 1-MCP treated tomatoes. Significant difference was found between the 1-MCP treated and the control tomatoes. Up to the 14th day, weight loss for 1-MCP treated tomatoes was lower than control tomato, however, enhanced weight loss was observed later and reached 3.32% on fully ripen stage (25th day). Similar decrease in weight during post-harvest storage was reported for the application of 1-MCP, GA in different fruits (Ahmad et al., 2013; Deaquiz et al., 2014; Duguma et al., 2014; Jeong et al., 2003; Khan and Singh, 2008; Rahman et al., 2014). Slight increase in weight during post-harvest storage was also reported for SA in plum (Davarynejad et al., 2015).
Figure 1. (A) Standard tomato ripening color chart. (B) Weight loss (%) of tomato during post-harvest storage at 20±4 ºC and 70±5 % RH for the application of Ethylene Inhibitors. Vertical bars represent standard deviation of 6 independent samples.
Peel color of tomato is typically the most common physical parameter to assess the progress of ripening. Therefore, the effect of ethylene inhibitors on the extent of ripening was initially assessed by investigating the tomato peel color change. Treatments imparted significant changes on the peel color of tomatoes during post-harvest storage (Figure 2A and B). The peel color started to change rapidly from 1st day for SA treated and control tomatoes and reached color stage-6 on the 9th and 12th day, respectively. However, GA, MA, Ethanol and 1-MCP treatment delayed peel color progression. MA and Ethanol treated tomatoes reached color stage-6 on the 14th and 17th day of post-harvest storage, respectively. GA and 1-MCP treated tomatoes reached color stage-6 on 21st and 25th day, respectively, which indicates the superior efficacy of these inhibiting agents in delaying the tomato ripening process.
The control tomatoes reached color stage-6 on 12th day of post-harvest storage but SA treated tomatoes reached color stage-6 on 9th day, which indicates that SA failed to delay tomato ripening. Similar result has been reported earlier for SA on plum at low concentration (Davarynejadet al., 2015). From Fig. 2B, it was clear that MA, Ethanol, GA and 1-MCP treatment delayed peel color change and hence ripening of tomato by 2, 5, 9 and 13 days, respectively. Consistent with our observation, it has been earlier reported that application of 1-MCP delayed the color change of tomato (Miret al., 2004), banana (Ding and Darduri, 2009). Similarly, it has been reported earlier that the color change was delayed by the application of GA on banana (Dugumaet al., 2014) and ethanol on tomato (Saltveit and Sharaf, 1992).
Figure 2. Color stage (A) and days taken to reach color stage-6; (B) of tomato during post-harvest storage at 20±4 ºC and 70±5 % RH for the application of Ethylene Inhibitors. Vertical bars represent standard deviation of 6 independent samples.
The total soluble solid (TSS) content of fully-ripen tomato was measured for different ethylene inhibitor treated tomatoes (Figure 3A). TSS of control and 1-MCP treated tomatoes were found similar (3.60%), which is consistent with earlier finding (Morettiet al., 2002). Similarly, l-MCP was reported to have no effect on TSS in carrots and lettuce (Fan and Mattheis, 2000). A slight decrease in TSS was observed for Ethanol and MA treated tomatoes. Tomatoes treated with Ethanol and MA had an average TSS of 3.25% and 2.84%, respectively. However, the opposite phenomenon was observed for SA and GA treated tomatoes. The TSS of SA and GA treated tomatoes were slightly higher (3.69% and 3.68%) than control tomatoes. Similar result was reported for GA on mango (Islam et al., 2013) and for SA on Kiwifruit (Bal and Celik, 2010). As significant decrease in TSS indicates a decrease in food quality, MA and ethanol might affect the food quality of tomato unlike SA, GA and 1-MCP.
The titrable acidity (TA) equivalent to citric acid content in tomato was also observed (Figure 3B). TA value was affected slightly indicating slight change in food quality among the treated tomatoes. The average value of TA was 0.240% in the control tomatoes. TA value was not affected by the application of GA and Ethanol, compared with the control tomatoes. Tomatoes treated with SA and MA had an average TA of 0.221% and 0.253% respectively. However, TA value was 0.30% for the 1-MCP treated tomatoes which was 6% higher than the control tomatoes. Similar results have been reported earlier. Pre and post-harvest treatment of SA changed TA value of fruits like strawberry (Lu et al., 2011), Kiwifruit (Bal and Celik, 2010) and Apple (Kazemi et al., 2011). However, GA significantly affected the TA value in mango (Islamet al., 2013). 1-MCP also changed TA value in lettuce and apples (Fan and Mattheis, 2000), and papaya (Bron et al., 2006).
Figure 3. Total Soluble Solids (%) (A), Titrable Acidity (%) (B), pH (C) and Ascorbic Acid content (mg g-1 FW) (D) at completely ripen stage of tomatoes during post-harvest storage at 20±4 ºC and 70±5 % RH for the application of Ethylene Inhibitors. Vertical bars represent standard deviation of 4 independent samples.
Different values of pH were observed in the tomatoes treated with different ethylene inhibitors which indicate the pH of tomato is significantly affected by the treatment (Figure 3C). The lowest average value of pH was observed for SA treated tomato (4.53) whereas the control tomatoes had average value of 4.68 which indicated that SA treated tomatoes were more acidic then the control. Tomatoes treated with 1-MCP, GA, MA and Ethanol had an average pH of 4.60, 4.77, 4.74 and 4.64 respectively, which indicated a slight change in pH with respect to the control. The value of pH has been earlier reported to be affected by 1-MCP in banana (Ding and Darduri, 2009) and by GA in mango (Islamet al., 2013).
Ascorbic Acid is considered as one of the most essential vitamins for human nutrition. At the end of the storage period the amount of Ascorbic Acid was analyzed and no significant differences were noticed among control, 1-MCP, SA and MA treated tomatoes (Figure 3D). The average value of Ascorbic Acid was 0.24 mg g-1 FW in the control tomatoes. Therefore, it is evident that these ethylene inhibitors had no effect on ascorbic acid content and thus in food quality of tomato. Similar observation was reported for 1-MCP in banana (Ding and Darduri, 2009; Rahmanet al., 2014), papaya (Bronet al., 2006), plum and for SA in Kiwifruit (Bal and Celik, 2010). However, ascorbic acid was increased significantly for GA and ethanol treated tomatoes and their values were 0.27 and 0.43 mg g-1 FW, respectively. Similar observation was reported for GA in banana (Dugumaet al., 2014) and for ethanol in Mung bean (Goyal et al., 2014).
Figure 4. (A) Weight loss (%) tomatoes during post-harvest storage at 20±4 ºC and 70±5 % RH for the application of 1-MCP at different concentration. Color stage (B) and days taken to reach color stage-6 (C) of tomatoes during post-harvest storage at 20±4 ºC and 70±5 % RH for the application of 1-MCP at different concentration. Vertical bars represent standard deviation of 6 independent samples.
Optimizing the doses of 1-MCP
Earlier, it was observed that 1-MCP increased the shelf-life of tomato significantly with very slight effect on the food quality. Therefore, the optimum concentration of 1-MCP to maximize the shelf-life and to minimize the alteration of food quality was investigated. The weight loss during post-harvest storage of tomatoes treated with different concentration of 1-MCP showed very little differences among the treated tomatoes and the control (Figure 4A). The weight loss of tomatoes treated with 200, 500, 800 and 1100 µg/L of 1-MCP on 22nd day varied between 7.71-8.74%. Tomatoes treated with 500µg/L of 1-MCP exhibited minimum weight loss whereas tomatoes treated with 800µg/L of 1-MCP exhibited maximum weight loss. This is consistent with earlier finding (Wrzodak and Gajewski, 2015).
As seen in Figure 4B, different concentration of 1-MCP treatment significantly delayed color development of tomato. The control tomatoes reached color stage-5 on 5th day, whereas peel color stage was between 1 and 3 for all the 1-MCP treated tomatoes at that time. However, retention of skin color was significantly affected by increase in the 1-MCP concentration. Tomatoes treated with 200, 500 and 800 µg/L of 1-MCP ripened completely on the 22nd, 29th and 31st day, respectively. Nevertheless, higher concentration didn’t improve the retention of skin color much (1100 µg/L, 25th day). It is clear from the figure that 1-MCP treatment retain the skin color of tomato in color stage 3 to 5 for longer time than the control and therefore, 1-MCP treatment can be applied commercially to increase the shelf life in semi-ripen stage longer time at ambient condition.
It is clear from Figure 4C that delay in tomato fruit ripening significantly depends on the concentration of 1-MCP. The control tomatoes were fully ripen on 11th day but the treated tomatoes succeeded to retain skin color by that time. Delay of tomato fruit ripening increased with the increase of treatment concentration up to 800 µg/L. Tomatoes treated with 200, 500 and 800 µg/L of 1-MCP delayed ripening of tomato by 11, 18 and 20 days. However, higher concentration didn’t follow the trend (1100 µg/L of 1-MCP delayed ripening of tomato by 14 days). Similar result was observed for different fruits and vegetables (Morettiet al., 2002; Rahmanet al., 2014). These results indicate that the most effective and economic concentration of 1-MCP was 500 µg/L as ripening was not delayed significantly beyond this concentration.
All concentrations of 1-MCP treatment decreased the TSS in tomato compared to control, however, TSS content increased slightly with increase in 1-MCP concentration up to 800 µg/L and beyond that concentration, TSS decreased again (Figure 5A). TSS of the control sample was 3.78% whereas, TSS of tomatoes treated with 200 and 500 µg/L of 1-MCP were 3.21% and 3.09%, respectively. The TSS of the tomatoes treated with 800 µg/L of 1-MCP were very similar to that of the control tomatoes. The TSS content of tomatoes treated with 1100 µg/L of 1-MCP was 3.44%. Similar effect on TSS was reported in ‘Delicious’ and ‘Fuji’ apples (Fan et al., 1999), banana (Rahmanet al., 2014) and papaya (Bronet al., 2006).
The effect on TA content of tomato due to different concentrations of 1-MCP was investigated and it was noticed that different concentrations of 1-MCP treatment affected the TA content in tomatoes compared to control (Figure 5B). The TA of the control tomatoes was 0.194%. The TA content of the tomatoes treated with 500 µg/L of 1-MCP were almost similar to that of the control tomatoes. Tomatoes treated with 200, 800 and 1100 µg/L of 1-MCP had an average TA of 0.164%, 0.188% and 0.176%, respectively. Such reduction in TA indicates the degradation in the quality of tomatoes. So, these concentration of 1-MCP treatment failed to maintain food quality compared with the control. Similar effect in the TA value in lettuce and carrots (Fan and Mattheis, 2000) was reported for 1-MCP treatment. Therefore, 500 µg/L of 1-MCP can be considered as high enough concentration considering as food quality (TA). pH values of the tomatoes were found to be increased with the increase in 1-MCP concentration (Figure 5C), however pH value deceased in high concentration (1100µg/L). The lowest average value of pH was found for the tomatoes treated with 1100µg/L of 1-MCP (4.35), whereas the tomatoes treated with 500µg/L of 1-MCP had pH value very similar to that of the control tomatoes. Tomatoes with control, 200, 500 and 800 µg/L of 1-MCP had pH value of 4.58, 4.82, 4.67 and 5.02, respectively. Similar effect in pH was reported for the application of 1-MCP on Cavendish banana (Ding and Darduri, 2009).
Figure 5. Total Soluble Solid (%) (A), Titrable Acidity (%) (B), pH (C) and Ascorbic Acid content (mg/100gm) (D) at completely ripen stage of tomatoes during post-harvest storage at 20±4 ºC and 70±5 % RH for the application of 1-MCP at different concentration. Vertical bars represent standard deviation of 4 independent samples.
The amount of ascorbic acid was analyzed when tomatoes were completely ripen. The treatment slightly decreased the ascorbic acid in tomatoes compared with the control (Figure 5D). The lowest value of ascorbic acid was noticed in the tomatoes treated with 200µg/L of 1-MCP (0.187 mg g-1 FW). Interestingly, the amount of ascorbic acid in tomatoes increased with the increase in concentration of 1-MCP and tomatoes treated with higher concentration of 1-MCP (1100µg/L) had ascorbic acid content similar to the control tomatoes. Tomatoes treated with 500, 800 and 1100µg/L of 1-MCP had ascorbic acid of 0.204, 0.207, 0.215 mg g-1 FW, respectively, whereas the control tomatoes had 0.218 mg g-1 FW. Concentration of 1-MCP treatment had negligible effect on ascorbic acid content of tomato at higher concentration. Similar observation was reported on banana (Rahmanet al., 2014).
Results of the present study demonstrate that, ethanol, GA and 1-MCP were effective whereas SA and MA failed in delaying the ripening of tomato. However, 1-MCP was the most effective ethylene inhibitor. The effectiveness of 1-MCP in delaying the ripening process of tomato without affecting the food qualities (namely, TSS, TA, pH and Ascorbic Acid) varied slightly with the change in 1-MCP concentrations. As 1-MCP at lower concentration (200 to 800 µg/L) significantly delayed the ripening process but the food quality varied slightly in this concentration range. Therefore, under the conditions tested in this study, 500 µg/L solution of 1-MCP can be considered as the optimum concentration in terms of maximizing the post-harvest storage life of tomato at 20±4 ºC and 70±5 % RH without any significant effect on food quality. The results of this study revealed that 500 µg/L of 1-MCP may have post-harvest applications and can be used for delaying the ripening of harvested mature green tomato whereas hazardous chemical like Formaldehyde is being used in developing countries to increase the shelf-life of fruits and vegetables. The beneﬁts and effectiveness of ethylene inhibitor like 1-MCP in delaying the ripening and ripening-related changes in fruits and vegetables should be considered for commercial application. Use of this ethylene inhibitor, can offer flexibility and convenience, thus can be an attractive alternative to hazardous chemicals currently being used without authorization in developing countries for the post-harvest management of fruits and vegetables.
The authors would like to acknowledge the support of Bangladesh Agriculture Research Institute (BARI) during this study.
Conflict of interest
The authors declare that there is no conflict of interest regarding the publication of this paper
SA had conceived the idea of the study. SA and SB had designed the experiments. SB, TR, OH, AM, RSL, TZ and DG had performed different parts of the experiments. SB, OH, AM and SA had written and finalized the manuscript.
Ahmad A, Ali ZM and Zainal Z. (2013). Delayed softening of papaya (Carica papaya L. cv. Sekaki) fruit by 1-methylcyclopropene (1-MCP) during ripening at ambient and low temperature storage conditions. Australian Journal of Crop Science. 7(6): 750-757.
Anthon GE, LeStrange M and Barrett DM. (2011). Changes in pH, acids, sugars and other quality parameters during extended vine holding of ripe processing tomatoes. Journal of the Science of Food and Agriculture. 91(7): 1175-1181.
Bal E and Celik S. (2010). The Effects of Postharvest Treatments of Salicylic Acid and Potassium Permanganate on the Storage of Kiwifruit. Bulgarian Journal of Agricultural Science. 16(5): 576-584.
Baldwin EA. (1993). Citrus Fruit. In: Seymour GB, Taylor JE, Tucker GA, editors. Biochemistry of Fruit Ripening. Dordrecht: Springer Netherlands. p. 107-142.
Bapat VA, Trivedi PK, Ghosh A, Sane VA, Ganapathi TR and Nath P. (2010). Ripening of fleshy fruit: Molecular insight and the role of ethylene. Biotechnology advances. 28: 94-107.
Barry CS and Giovannoni JJ. (2007). Ethylene and fruit ripening. Journal of Plant Growth Regulation. 26: 143-159.
Barua S, Rahi T, Ullah E, Ghosh D and Ahmed S. (2015). Delay in fruit ripening : a promising approach for reduction of spoilage and use of hazardous chemicals in Bangladesh. International Journal of Agronomy and Agricultural Research (IJAAR). 6: 163-172.
Bron IU, Jacomino AP and Pinheiro AL. (2006). Influence of ripening stage on physical and chemical attributes of ‘Golden’ papaya fruit treated with 1-methylcyclopropene. Bragantia. 65(4): 553-558.
Bugaud C, Deverge E and Daribo M-O. (2011). Sensory characterisation enabled the first classification of dessert bananas. Journal of the Science of Food and Agriculture. 91: 992-1000.
Costa AIA, Dekker M and Jongen WMF. (2000). Quality function deployment in the food industry: a review. Trends in Food Science & Technology. 11(9-10): 306-314.
Davarynejad GH, Zarei M, Nasrabadi ME and Ardakani E. (2015). Effects of salicylic acid and putrescine on storability, quality attributes and antioxidant activity of plum cv. ‘Santa Rosa’. Journal of Food Science and Technology. 52(4): 2053-2062.
Deaquiz YA, Álvarez-Herrera J and Fischer G. (2014). Ethylene and 1-MCP affect the postharvest behavior of yellow pitahaya fruits (Selenicereus megalanthus Haw.). Agronomia Colombiana. 32: 44-51.
Ding P and Darduri K. (2009). Responses of Musa AAA Berangan to 1-methylcyclopropene. Pertanika Journal of Tropical Agricultural Science. 32: 125-132.
Duguma T, Egigu MC and Muthuswamy M. (2014). The effects of gibberellic acid on quality and shelf life of banana (Musa spp.). International Journal of Current Research and Review. 6: 63-69.
Fan X, Blankenship SM and Mattheis JP. (1999). 1-Methylcyclopropene Inhibits Apple Ripening. Journal of the American Society for Horticultural Science. 124(6): 690-695.
Fan X and Mattheis J. (2000). Reduction of Ethylene-induced Physiological Disorders of Carrots and Iceberg Lettuce by 1-Methylcyclopropene. HortScience. 35: 1312-1314.
Goyal A, Siddiqui S, Upadhyay N and Soni J. (2014). Effects of ultraviolet irradiation, pulsed electric field, hot water and ethanol vapours treatment on functional properties of mung bean sprouts. Journal of food science and technology. 51(4): 708-14.
Grichko V, Serek M, Watkins CB and Yang SF. (2006). Father of 1-MCP. Biotechnology advances. 24(4): 355-6.
Hernandezmunoz P, Almenar E, Valle V, Velez D and Gavara R. (2008). Effect of chitosan coating combined with postharvest calcium treatment on strawberry (Fragaria×ananassa) quality during refrigerated storage. Food Chemistry. 110(2): 428-435.
Huber DJ. (2008). Suppression of Ethylene Responses Through Application of 1-Methylcyclopropene: A Powerful Tool for Elucidating Ripening and Senescence Mechanisms in Climacteric and Nonclimacteric Fruits and Vegetables. HortScience. 43(1): 106-111.
Iqbal M, Khan MN, Zafar M and Munir M. (2012). Effect of harvesting date on fruit size, fruit weight and total soluble solids of feutrell’s early and kinnow cultivars of madarin (Citrus reticulata) on the economic conditions of farming community of Faisalabad. Sarhad Journal of Agriculture (Pakistan). 28(1): 19-21.
Islam M, Khan M and Sarkar M. (2013). Post harvest Quality of Mango (Mangifera Indica L.) Fruit Affected by Different Levels of Gibberellic Acid During Storage. Malaysian Journal of Analytical Sciences. 17: 499-509.
Jeong J, Huber DJ and Sargent SA. (2003). Delay of avocado (Persea americana) fruit ripening by 1-methylcyclopropene and wax treatments. Postharvest Biology and Technology. 28: 247-257.
Kader AA. (2005). Increasing Food Availability by Reducing Postharvest Losses of Fresh Produce. Acta Horticulturae. 682: 2169-2176.
Kandungan K, Giberelik A, Mangga B, Indica M, Tuai L and Penyimpanan S. (2013). Postharvest Quality of Mango (Mangifera Indica L .) Fruit Affected by Different Levels of Gibberellic Acid During Storage. Malaysian Journal of Analytical Sciences. 17(3): 499-509.
Kazemi M, Aran M and Zamani S. (2011). Effect of Salicylic Acid Treatments on Quality Characteristics of Apple Fruits During Storage. American Journal of Plant Physiology. 6(2): 113-119.
Khan AS and Singh Z. (2008). 1-Methylcyclopropene Application and Modified Atmosphere Packaging Affect Ethylene Biosynthesis, Fruit Softening, and Quality of ‘Tegan Blue’ Japanese Plum During Cold Storage. Journal of the American Society for Horticultural Science. 133: 290-299.
Kitinoja L, Saran S, Roy SK and Kader AA. (2011). Postharvest technology for developing countries: challenges and opportunities in research, outreach and advocacy. Journal of the Science of Food and Agriculture. 91: 597-603.
Lolaei A, Kaviani B, Rezaei MA, Raad MK and Mohammadipour R. (2012). Effect of Pre- and Postharvest Treatment of Salicylic Acid on Ripening of Fruit and Overall Quality of Strawberry (Fragaria ananassa Duch cv. Camarosa) Fruit. Annals of Biological Research. 3(10): 4680-4684.
Lu X, Sun D, Li Y, Shi W and Sun G. (2011). Pre- and post-harvest salicylic acid treatments alleviate internal browning and maintain quality of winter pineapple fruit. Scientia Horticulturae. 130(1): 97-101.
Lyon BG, Robertson JA and Meredith FI. (1993). Sensory Descriptive Analysis of cv. Cresthaven Peaches-Maturity, Ripening and Storage Effects. Journal of Food Science. 58(1): 177-182.
Malundo T, Shewfelt R and Ware G. (2001). Sugars and Acids Influence Flavor Properties of Mango (Mangifera indica). Journal of the American Society for Horticultural Science. 126: 115-121.
Martinez GA, Chaves AR and Anon MC. (1994). Effect of Gibberellic-Acid on Ripening of Strawberry Fruits (Fragaria ananassa Duch). Journal of Plant Growth Regulation. 13(2): 87-91.
Mir N, Canoles M, Beaudry R, Baldwin E and Pal Mehla C. (2004). Inhibiting tomato ripening with 1-methylcyclopropene. Journal of the American Society for Horticultural Science. 129(1): 112-120.
Moretti CL, Araújo AL, Marouelli WA and Silva WLC. (2002). 1-Methylcyclopropene delays tomato fruit ripening. Horticultura Brasileira. 20: 659-663.
Osorio S, Scossa F and Fernie AR. (2013). Molecular regulation of fruit ripening. Frontiers in plant science. 4(June): 198-198.
Rahman MA, Hossain MA, Begum MM, Banu SP and Arfin MS. (2014). Evaluating the effects of 1-methylcyclopropene concentration and immersion duration on ripening and quality of banana fruit. Journal of Post-Harvest Technology; Vol 2, No 1 (2014).
Ranganna S. (1986). Flavouring Materials. Handbook of Analysis and Quality Control for Fruit and Vegetable Products. Tata McGraw-Hill Education. p. 242-286.
Raskin I. (1992). Role of Salicylic Acid in Plants. Annual Review of Plant Physiology and Plant Molecular Biology. 43(1): 439-463.
Saltveit ME, Jr. and Sharaf AR. (1992). Ethanol Inhibits Ripening of Tomato Fruit Harvested at Various Degrees of Ripeness without Affecting Subsequent Quality. Journal of the American Society for Horticultural Science. 117(5): 793-798.
Sowa S and Kondo AE. (2003). Sailing on the “C”: A Vitamin Titration with a Twist. Journal of Chemical Education. 80(5): 550-550.
Su H and Gubler WD. (2012). Effect of 1-methylcyclopropene (1-MCP) on reducing postharvest decay in tomatoes (Solanum lycopersicum L.). Postharvest Biology and Technology. 64(1): 133-137.
Turner D and Fortescue J. (2012). Bananas (Musa spp.). Oxford, UK: Wiley-Blackwell. p. 24-42.
Watkins CB. (2008). Overview of 1-Methylcyclopropene Trials and Uses for Edible Horticultural Crops. HortScience. 43(1): 86-94.
Wrzodak A and Gajewski M. (2015). Effect Of 1-MCP Treatment on Storage Potential of Tomato Fruit. Journal of Horticultural Research. 23(2): 121-126.