Dr Mukul Chandra Bora
(The writer is Director, Dibrugarh University Institute of Engineering & Technology. He can be reached at drmukulcbora@gmail.com)
Phytochemicals are naturally occurring organic chemical compounds which are produced by plants, fruits and vegetables ("Phyto" means "plant") to make their defence mechanism against the attacks of microbes. These chemicals are abundantly found in fruits, vegetables, grains, beans, and other plants and the research has shown that some phytochemicals may help to stop the formation of potentially cancer-causing substances (carcinogens). The complete benefits of these Phytochemicals can only be obtained if it is fresh and it helps human being to build their disease defence mechanism in their bodies. Although we consume a lot of fruits and vegetables which are stored and transported through a long-distance we are unable to get the full benefits of this food due to loss of the materials available due to the aforesaid activities. Phytoconstituents have had a considerable significance in the everyday life of humans for a long and with the advancement of modern sciences and technological innovations, a significant human interference in nature has been observed which leads to the enhancement of plant-based products in agro-pharma sectors. Commercial utilization of medicinal phytoconstituents is a valuable thing from a scientific as well as industrial point of view and in the last few decades, we have witnessed a lot of illegal commercial exploitation of phyto-resources. The Intellectual Property Rights (IPR) make conspicuous relation of balancing the use and protection of phytochemicals and the IPR is not only advocated equitable profit sharing with the indigenous peoples but also commands the sustainable use of phytoconstituents. Phytochemicals are precious for human nutrition.
Indoles, isothiocyanates, and sulforaphane from vegetables, such as broccoli, allylic sulphides from onions and garlic and isoflavonoids from soybeans are known as plant phytochemicals. These are present in high concentrations in raw foods but intensities are reduced during processing and handling.
The benefits of eating local foods: Let us define the people which only take locally produced seasonal food this type of people are called Locavore and they try to choose locally grown or locally produced seasonal food for their survival. Although there are many definitions of "local food", the concept is based primarily on distance and many people like to purchase locally produced food or by starting within their community, then moving out to the region, province, country and so on. This type of food consumption is the basis for the popular 100-mile diet (This is a self-imposed challenge that advocates to only eat things that are produced within a radius of 100 miles from their home. It not only includes fruit and vegetables but everything, including farm produce (if the animals had only been fed locally-sourced food as well), which promotes buying and eating food that's grown, manufactured or produced within a 100-mile radius of the consumer's home which in turn boost up the local economy.
Why eat 'local': These are just a few of the numerous potential benefits of eating local:
· It's good for the environment. Local food doesn't have to travel as far to arrive on your plate, so it helps reduce greenhouse gas emissions and contributes to improving our carbon footprint. It benefits the local economy, including supporting local farmers and other producers.
· It encourages sustainable agriculture and facilitates tracking the supply chain back to the point of origin to evaluate ecological practices.
· It ensures that food has passed some of the highest safety standards in the world. Very strict regulations regarding additives, pesticides, herbicides, etc., ensure that Canadian food is safe.
· It may have a higher nutrient value, as food that is grown and harvested locally is usually given more time to ripen. This does not, however, automatically mean that local food is necessarily more nutritious, as other factors come into play (see below).
· We might be biased, but we think eating local just tastes better. Have you ever tried any strawberry as good as a Quebec strawberry?
Are local foods more nutritious: Several factors influence the nutritive value of produce including crop variety, how it's grown, ripeness at harvest, storage, processing and packaging. Its vitamin and mineral content depends on the practices of people all along the line, from the seed to the table, whether or not the produce is local or transported from a distance.
Produce such as broccoli, green beans, kale, red peppers, tomatoes, apricots and peaches are susceptible to nutrient loss when harvested and transported from longer distances, while those that are heartier such as apples, oranges, grapefruit and carrots keep their nutrients even if they travel long distances.
According to a report published by Harvard Medical School, the concept of Healthy and Sustainable Food is defined as "What does a sustainable and healthy future mean when it comes to food production, consumption and resulting environmental impacts? With nearly a billion people globally going hungry and nearly two billion eating the wrong food, the answer is pressing – especially as we look to a future that needs to sustainably feed "10 billion by 2050." This Forum will explore how to avert dire consequences for human and planetary health through best practices and new technologies. Key questions will be how to amplify nutritious food production, prevent waste and secure supplies while protecting our environment in the process. The discussion will include the "planetary health diet" recently proposed by an international commission that emphasizes plant-based eating for better health and minimal ecological impact."
The impacts of different parameters which influence the loss of Phytochemicals concentration, loss of nutrients and nutritional values due to transportation, storage etc., are briefly enumerated in the following sections.
Temperature, Relative Humidity (RH) fluctuation, and weight loss: Temperature and Relative Humidity (RH) are the two major environmental factors that are crucial in maintaining the quality as well as the extension of shelf life of fresh fruits and vegetables. It was observed that the total loss in weight of crisp-head lettuce at three different stages of the supply chain within two provinces has exhibited a great variation with produce accumulating the greatest weight loss at the retail shelf. Significant weight loss (45.31%) occurred at the retail shelf than in storage where the weight loss was 25.55%, while the produce after transportation did not show any weight loss (0.00%). However, the magnitude of weight loss of lettuce failed weight loss increased significantly with increasing time (days) at the retail shelf and on Day 4 the weight loss was 64.6%. It is evident from those research outcomes that weight loss is the most important cause of post-harvest deterioration because it is associated with the saleable weight and the fluctuation of temperature and the RH are the two major causes for the observed weight loss in fruits and vegetables.
Loss of quality: Quality loss in fruits and vegetables are mainly occurred due to yellowing, rusty brown, stem discolouration, and wilting damage were significantly higher in lettuce at the retail shelf. The major reason for wilting was water loss due to transpiration through the stomata when the concentration gradient of the water vapour between the air spaces in the leaf and the surrounding environment was steeper. Furthermore, fluctuation of temperatures (high) or RH (low) was shown to affect the quality of leafy vegetables. The loss of water in cell wall degradation affects the texture, turbidity and visual appearance. The loss of phytochemicals concentrations due to RH and temperature are the responsible factors that influence the health benefits of fruits and vegetables due to changes of locations.
Variation in bioactive compounds: It is found in various research that a significant decrease in ascorbic acid, total chlorophyll content, and carotenoids were also observed in leafy vegetables. The loss of ascorbic acid content was also greatly reduced in the process starting from transportation to the retailer end. The influence of temperature on colour and chlorophyll degradation was also observed by Cantwell and Kasmire in their research in 2002. Loss of chlorophyll in the leaves leads to an increase in the intensity of yellow colour in the leaves and yellowing of leafy vegetables is associated with the activity of peroxidase and lipoxygenase. Chlorophyll is responsible for the green colour and is used as one of the quality parameters that determine consumer purchasing power. Loss of chlorophyll content at the retail shelf affected consumer preference for purchasing lettuce and influenced the marketing of lettuce in this study. Loss of chlorophyll is primarily due to the senescence that is associated with loss of membrane lipids and proteins, thus leading to textural changes and cell death. Loss of ascorbic acid content from the outer and middle lettuce leaves was related to its reduced moisture content caused as a result of lower RH and the higher temperatures at the retail shelf. Ascorbic acid content was reported to improve the lightness of strawberries, peaches, and apples. Earlier research reports observed that about 5%–12% loss of ascorbic acid occurs at 30° and 40°C, respectively, during the 24-hour delay between harvesting and processing. It is important to note that the daily requirement of ascorbic content for a man is 90 mg and for women, 75 mg and the research confirmed that about 81% of the ascorbic acid content was lost on the retail shelf on the 4thDay of storage and was reported by others that similar reduction trends were observed with light intensity and the ascorbic acid content of lettuce at the retail shelf. The increased browning in fruits and vegetables are solely responsible for declination in ascorbic acid content at the retail shelf. The total carotenoid content was also reduced by 22.9% and 47.8% at the storage point and the retail shelf and the loss of carotenoids were significantly higher at 25°C in leafy vegetables subjected to higher temperatures during thermal treatments, which have been reported to induce loss of carotenoids in vegetables.
Loss in mineral contents: Loss of mineral contents such as Potassium (K), Phosphorus (P), Calcium (Ca), Magnesium (Mg), Iron (Fe), Zinc (Zn), Manganese (Mn), Copper (Cu), and Boron (B) was significantly higher at the retail shelf. The reduction of K, P, Ca, and Mg at the retail shelf was 23.5%, 21.3%, 24.8%, and 14.3%, respectively and the levels of K, P, and Ca in lettuce heads did not vary significantly between the transport and storage points. The trace mineral elements such as Fe, Zn, Mn, Cu, and B were reduced by 48.8%, 34.0%, 49.7%, 79.8%, and 23.0% at the retail shelf. The loss of mineral elements at the retail shelf was also reported by various researchers in the case of leafy vegetables. The loss of mineral elements occurs due to the higher temperature at the retail shelf that had favoured the metabolic changes and senescence. Also, the minerals present in fruits and vegetables like iron and calcium can chemically alter and interact with other compounds and the storage conditions can also influence the oxidation state of minerals (Fe and Cu) that can reduce the solubility and the bioavailability of these minerals.
Economic losses: It is observed that the cumulative losses at the storage and retail shelf were 36.7% and 53.1%, respectively after two days of storage. The geographic site of production and its distance together with the conditions during agricultural production, postharvest handling, and storage conditions at the farm could have played a vital role in determining the quality. It is quite evident that the economic losses associated with fruits and vegetables increased along the supply chain.
Although there are many types of losses incurred in the case of fruits and vegetables due to storage and transportation but the issue of loss of reduction and changes in the Phytochemicals and nutrients are the vital parameters and hence the locally available food can bring health and wealth for the population of that area. We have observed the minimization of immunity in the human population during the COVID-19 pandemic due to which we have lost a lot of our brothers and sisters amongst us. It is noteworthy to mention that the father of modern medical Science Hippocrates in 400 BC said "Let thy food be thy medicine and medicine be thy food, and used to emphasize the importance of nutrition to prevent or cure disease. We can only lead a healthy life with food and vegetables which are full of nutrients. In short, the locally grown fruits and vegetables have the following benefits together with the boost to the local economy. The locally grown vegetables have got the characteristics of full of flavour, more nutrients, benefits to the environment, safer food supply etc. According to research publications published in British Medical Journal (2020), wherein Sarah Downer and colleagues concluded that Integration of food is medicine interventions into healthcare depends in large part on new investment in research to add to the evidence base. Improved clinician training and referral capacity, together with increased financial support for interventions both in and outside the healthcare system, will help to ensure that patients are assessed and referred to appropriate interventions available in every community. Access to interventions will be supported by the proliferation of organizations and entities that can deliver a range of food and nutrition interventions, some of which are quite complex. In the US, for example, an increasing number of non-profit and for-profit entities are contracting with the healthcare system to provide these services, many for the first time. The global pandemic of COVID-19 has brought the fragility of food and healthcare systems across the globe into sharp relief, with skyrocketing rates of food insecurity and people with diet-related illnesses struggling with increased barriers to accessing healthy food. Healthcare systems that integrate food are medicine interventions will enable more resilient systemic responses to such crises. An integrated system will support the infrastructure of food is medicine providers and access pathways that can be used to immediately meet increased demand for healthy food support. The consequences of poor health caused by poor diet affect many sectors (resulting in high healthcare spending that diverts funds from other policy priorities such as education and enhancing economic prosperity); clinicians working to advance integration have a compelling case to make to a diverse range of decision-makers. As healthcare systems continue to evolve to tackle the global crisis of nutrition-related disease, food is medicine interventions should be held to rigorous standards when decisions about implementation, coverage, and care are made. But they can no longer be categorically excluded as outside of or ancillary to healthcare delivery, as they have been in the past across many healthcare systems. Integration of food and nutrition interventions into healthcare holds significant promise for meeting immediate nutrition needs while working in harmony with broader, long-term health and food system reforms. So we have come to know that food plays an important role in healthy living and it will only make us healthy if all the components in the food remain unaltered and hence local food only makes it possible.