These fruits and vegetables displayed time-dependent differences in insect resistance strongly suggesting temporal fluctuations in diverse metabolites, some of which may have important human health impact. Whether continued promotion of circadian periodicity postharvest can also improve longevity of tissue integrity and phytochemical content in diverse vegetables and fruits, as we have shown with kale, cabbage, lettuce, and spinach, remains to be investigated.Plant-based meat is a brand new food category that has attracted widespread media and investor attention since its introduction in 2017. In contrast to other meat substitutes , plant-based meat products are being marketed as indistinguishable in taste and appearance to meat. Producers of plant-based meats aim to compete more directly with, and eventually replace, meat. The appearance of these items beginning in 2017 has drawn a significant amount of interest from environmentalists, conservationists, and animal welfare advocates, as they hope it will result in lower demand for beef and wilderness conversions to pasture required to raise it . The potential is massive. Meat and dairy account for 15% of global greenhouse gas emissions , and the emissions produced by a kilogram of beef can be as much as ten times higher than pork or chicken and twice as high as the second worst offender, lamb . For those concerned about biodiversity, conversion of land to grazing pasture or feed agriculture is the leading cause tropical forest deforestation in much of the world . There is a lack of political will to support the imposition of new taxes on meat products.
Therefore, square plant pots cycling of light treatment with darkness periods may not only maintain clock function but may also avoid physiological damage that may occur in plant tissues under too much light. In addition to improvement of green leafy vegetable appearance by postharvest storage under light/dark cycles, we found that this postharvest storage treatment of plant crops may improve human health benefits through maintenance of phytochemical content . Chlorophyll, responsible for the visual appeal of green leafy vegetables, also has beneficial impact upon human health upon ingestion. Chlorophyll can limit efficacy of carcinogens, such aflatoxin B1 and can activate Phase II detoxifying enzymes. Glucosinolates, sulfurcontaining compounds that play a major role in Brassicaceae plant herbivore defense , also underlie the human health benefits attributed to Brassicaceae vegetable consumption. For example, the glucosinolate glucoraphanin has potent anticancer activity. Previous studies have shown that glucosinolate levels can be maintained by refrigeration or exposure to radiation; here we find that post-harvest storage under light/dark cycles can also lead to sustained glucosinolate levels .Light/dark cycles also maintain the circadian clock function of other edible crops after harvest, including zucchini, carrots, sweet potatoes, and blueberries.
As such, the only viable strategy for plant-based meat to gain market share from traditional animal-derived meat is to compete on price and taste. Some futurists have suggested that technological advancements may make this inevitable in the future , but currently PBM is far more expensive. While alternative protein sources have gained market share in recent years, it remains to be seen whether they will be able to replace their animal-based Researchers have sought to better understand the potential for PBM, but because it is so new, much work has been limited to stated preference surveys, which rely on hypothetical choices. Researchers have generally found that even if offered large price reductions, the market share for PBM is likely to stay below 20% of ground meat . Research that takes advantage of retail scanner data has sought to examine substitution patterns, but without individual level data, can only say limited things about who the customers are . Many of the existing stated preference studies identify those already predisposed to meat alternatives as the most likely to purchase PBM, and also find a not insignificant amount of the demand comes from those being pulled into the meat market , yet researchers have also found that most PMB purchasers also bought meat or ground meat. Understanding both who PBM purchasers are in the real world and how their consumption is affected is critical to understanding if PBM has a real potential to replace beef and other meats, or if PBM is simply a new category of meat alternative that is mainly competing with other kinds of low emissions foods like veggie burgers, tofu, or chicken. As data availability has increased some researchers have been able to use household scanner data to begin to answer these questions, but there are limited sample sizes due to the small size of PBM market share.
In particular, this work has shown us that PBM purchasers did not reduce their ground beef purchases after they first bought PBM, and that just more than half of PBM purchasers bought it again . This paper has the advantage of proprietary data from a nationwide grocery chain that goes beyond home scanner data. With this data, I am able to draw a very large sample of households who have bought PBM at least once and have a long history of their purchases before and after. With this dataset, I am able to draw more fine conclusions about what attributes are related to purchasing and repurchasing PBM, as well as if PBM is able to spread to customers who are more likely to be substituting away from meat. In addition, because of how promotional pricing is determined at this nationwide chain, I am able to run event study regressions to test the theory that PBM has is a robust substitute for beef in grocery stores.The data for this study are proprietary data from a single nationwide grocery store chain, which operates in a number of different regions and under a number of different store ordividion names. Over 90% of sales across all brands are linked to an individual membership card that is theoretically assigned to a single household, although some people may share their membership card. When a customer applies for a membership card, some but not all have provided certain information that has allowed the grocery chain to match them with data from a credit company who provides estimates of the head of household’s age and race1 , and the size and income of the household. Prior studies using person level scanner data have been limited by the number of households that have ultimately purchased plant based meat. In order to ensure a large sample size, every household that purchased plant-based meat from its first limited introduction in 2017 to the end of 2019 was included, and a random sample of all households who did not purchase PBM in the same period was included as a comparison. While PBM was only first introduced in limited stores in mid 2017, all purchases since the beginning of 2016 are included in the data. This allows me to characterize households by their purchases in prior periods, as well as flexibly examine what types of purchases could ultimately predict who will buy PBM and who will rebuy it, plastic potting pots with the ultimate aim of trying to better understand if PBM are attracting the types of customers who are likely to substitute it for real meat. About 40% households did not have a full credit data match, either because they did not share enough data when they signed up for their membership card to be linked in the credit company’s database, or because one of the demographics estimates was missing for other unknown reasons. Households whose first trip was later than the 12th week of 2016 and whose last trip was before the 40th week of 2019 were also dropped. The spread of average trips per week per household between those that had and those who hadn’t bought PBM were found to be fairly different. This makes intuitive sense, as households that recorded few trips were more unlikely to have purchased any specific product item coded as a UPC. As a result the sample was trimmed to make the distribution of trips more similar: only households with more than 0.85 trips per week and less than 5.85 trips per week were included.
After all these cuts, we were left with 134,167 households who had bought PBM at least once and 60,269 households that had never bought PBM. In order to test if political partisanship has had an effect on demand for PBM, an additional demographic variable was created by connecting the zipcode of the most frequented store by each household to precinct level voting data from the 2016 presidential election compiled by the New York Times. Because the precinct that a store is in might be different from the surrounding area, the percentile Clinton vote of each precinct’s surrounding area is used, which the New York Times describes as “a measure based on the choices of the nearest 100,000 voters, as well as those within a 10-mile radius”. Plant-based meat beef were first rolled out in select areas in mid 2017, so the entire 2016 year is used as a pre-period to establish what households spent their money on before PBM existed. Five different pre-period variables were created due to assumptions of importance. Four variables were defined as the percent of expenditures in the pre-period that were spent on meat, ground beef, veggie burgers, and tofu. In addition, a household specific low meat indicator was defined as equal to one if a household spent less than 5% of expenditures in the pre-period on any meat. In order to expand the potential important relationships of pre-period purchases to not just the four goods of interest, but to any goods, two levels of UPC categorization used by the grocery chain were used. All UPCs are organized into 57 ’Groups’ and the more specific 459 ’Categories’ and those divisions were used for percent of expenditures in the pre-period calculations.There are three outcomes of interest: buying plant-based meat, rebuying PBM, and the changing demographics of who is buying PBM for the first time. Simply buying PBM is of obvious interest, but rebuying it may be even more important. If PBM is going to replace real meat, it will have to become a regular part of customers’ market basket. Simply knowing who the buyers and rebuyers of PBM are will not in itself provide a causal estimate of how much meat we expect PBM to replace, but it can tell us how optimistic we are about its ability to outcompete meat. Even the most optimistic PBM evangelists do not expect PBM to make a large dent in meat sales this early in its existence, but they do often cite the fact that 80 to 90% of PBM customers also eat meat. The implication is that PBM is not just for vegetarians, but will slowly muscle out meat in these customer’s diets. While this simple fact has been shown to be true, a much closer look at who is buying and rebuying PBM will tell us more about its potential as a meat killer. Because I observe grocery sales up until the last day of 2019, however, some customers have far longer to rebuy from their first purchase than households that bought near the end of 2019. If I used a simple 1/0 variable of rebuy, then I would find that early first time buyers were far more likely to have rebought, but as will be discussed in the next paragraph, there is reason to believe that later first time buyers may be different from earlier ones, so if this timing issue is not corrected for, we may mistake these changes in who is in the market for PBM as related instead to who is rebuying it. Therefore, I limit the rebuy decision to 12 weeks after the first buy for each household, and I drop all households who bought their first PBM item within 12 weeks of the end of 2019. Less obvious is why I care about the timing of when households first bought PBM. The proponents of PBM market it as not a better veggie burger, but as a whole new category of food, so the data are witnessing how a brand new option enters the grocery market. In mid 2017, when PBM was first offered for sale on grocery store shelves, it would not be surprising if many of the first time customers were highly knowledgeable about meat and animal alternatives and that those purchases were unlikely to be replacing much meat. That, however, is much less important than how the market evolves.