Additionally, the adsorption works performed by Beaver and Medina-Plaza extend from 0 to 15% ethanol by volume solutions. Extensions of this model to extraction times greater than 14 days, or outside of the temperature and ethanol ranges, would necessarily be extrapolations. All kinetic parameters are assumed to be a function of temperature only; ethanol dependence is captured in the adsorption equilibrium relationships. The proposed model groups all phenolics into three pseudo-species , rather than examining individual compounds. Further, anthocyanin concentrationswere measured in Lerno by Reversed Phase High Performance Liquid Chromatograph with a diode array detector. While the data indicate a decrease in free anthocyanin concentration towards the end of fermentation, the reaction products are not clear. Further improvements to this model would include parsing out the actions of specific phenolic to better predict overall anthocyanin and tannin behavior. Finally, this model assumes a homogenous mixture of grape solids and liquid. This is a tolerable assumption in a small fermenter, which is frequently pumped-over, such as the partially full 120 L working volume fermenters used in Lerno to collect the data used in this model. Diffusive-convective mass transfer will need to be considered when this work is extended to large industrial tanks. Despite these limitations, this model successfully predicts experimental behavior over a wide range of processing temperatures and times, dutch bucket hydroponic and is applicable to most red wine fermentations of industrial interest.Raspberry fruit are produced on a perennial shrub belonging to the vastly diversified Rubus genera of the Rosaceae family.

There are mainly two types of raspberries: red and black. Yellow raspberries are a mutated version of red raspberries that prevents the formation of red color . Purple raspberries are a hybrid between black and red raspberries. Raspberries are an aggregate fruit, a combination of individual drupelets that stay together with the help of an invisible hair-like structure. Each small drupelet is developed from a carpel, a significant characteristic of Rubus, where the mesocarps become fleshy and the endocarps become hard and form a tiny pit that encloses a single seed within each drupelet. The drupelets separate from the receptacle at harvest, creating a hollow, thimble-shaped fruit. Cane traditionally refers to aerial raspberry shoots but also often refers to rooted suckers . Raspberry plants generally start fruiting in the second year and can continue up to 15 years if properly managed. However, the canes are biennial. Usually, the cane grows in one year and fruits the next year. Canes sprouting in the first year are called primocanes , and in the second year are called floricanes . Both canes are present during the growing season . Primocane-fruiting types can produce two crops per year; onein the summer from the floricanes and the other in the fall from the primocanes. With the onset of cold temperatures, floricanes often go into a period of dormancy. Six weeks or more at 4℃ or lower is required to break dormancy. After fruiting, the entire cane senesces and dies. When second-year canes are flowering, first-year canes are growing from the crown or roots. Like other brambles, raspberry is a self-pollinated species . Fruit development occurs for 30-36 days in most cultivars . The best yields take place under sunny, cool summer conditions . Recently, the use of the high tunnels has extended the berry cultivation season both at the beginning and the end. This extension enables growers to gain more profit from the market as berry prices are usually higher during early and late seasons . Like all crops, water is very important for raspberry production.

According to Prange and DeEll , lack of water can affect the production and quality of berry fruit after harvest. However, excessive water, mostly due to high rainfall during the fruit growing period, made raspberries more susceptible to mechanical damage during transportation and storage .The red raspberry is believed to have originated in Turkey’s Ide mountains. The Romans may have expanded raspberry cultivation throughout Europe. However, the British improved and popularized raspberries throughout the middle ages and had the plant exported to New York by 1771 . In the early 1900s, raspberry cultivation got its momentum, and in 1920, New York State growers harvested more than 10,000 acres of raspberries. In 2018, there were three major raspberry production regions: Russia, Europe , and the Pacific Coast of North America . World raspberry production has grown 80% over the last 10 years. From 2010 to 2019, production increased from 373,000 tons to 684,000 tons. . In 2020, the total area under raspberry cultivation in the United States was 16,900 acres producing 111,000 tons of raspberries valued at US$469 million. In California, there were 8,000 acres, valued at US$395 million for fresh raspberries only. Canada is the biggest importer of US raspberries, and in 2021, Canada imported a total of 24,400 tons of fresh raspberries valued at $154 million from the US .A fruit’s quality is generally assessed based on its visual appearance, texture, flavor, and nutritional compounds . Raspberry quality and shelf life can be adversely affected by a variety of pre-harvest and postharvest factors. Pre-harvest factors include genetics, environment, and cultural practices. Postharvest factors such as handling, transportation, storage temperature, condition and duration, relative humidity also play important role on maintaining raspberry fruit quality. Raspberry is renowned for its aroma and flavor. Raspberry is a non-climacteric fruit and their taste and flavor mostly develop while they are ripening on the plant. The ratio of sugar and organic acids determines raspberry taste . Soluble solids from 9 to 10% and titratable acidity from 1.5 to 1.8% constitute good raspberry taste according to De Ancos .

Wang et al. evaluated raspberry fruit harvested at 5%, 20%, 50%, 80% and 100% ripe and they concluded that berries that were 50% to 80% ripe developed the same degree of SS, TA, and sugars as berries that were 100% ripe, whereas berries that were 5 to 20% ripe neverattained those properties. There are many volatile compounds, notably, α and β-ionone, linalool, α and β-pinene, caryophyllene and citral, contributing to raspberry flavor . Berry purchases are linked to several factors, the most important being freshness and origin, while price does not play a significant role . Visual quality is also very important for raspberry and a good indicator of shelf life. Brighter color without any visible decay and leakiness is perceived as fresher. Krüger et al. categorized raspberries in three groups based on their ripening stage; semi-ripe, ripe and over-ripe. They concluded that semiripe raspberries were potentially more suitable for shipping while maintaining acceptable sensory quality .Consumers have always been concerned about food quality and appearance, in general. However, consumer preference has been shifting toward fruit flavor and nutritional qualities, including their composition and level of bioactive compounds, such as vitamins, minerals, fiber, and even phenolic compounds . Raspberry fruit are 85- 90% water, ~9% SS and the remaining are insoluble solids. Raspberry fruit contain 13.6–31.1 mg/100 g Vitamin C and 0.2–83.6 mg/100 g anthocyanins . These compounds vary by cultivar, harvest time, cultural practices, environment and weather conditions . Raspberry fruit also contain a broad range of polyphenolic compounds; phenolic acids, flavanols, anthocyanins, proanthocyanidins, and ellagitannins . These compounds have been extensively studied for their antioxidant capacity and impact on human health . High antioxidant capacity is believed to contribute to health benefits by ameliorating the detrimental effects of reactive oxygen species generated in the body through oxygen metabolism . Berry polyphenols also have been shown to protect against ROS-induced neurological diseases such as Alzheimer’s , and red raspberries have been reported to have a neuroprotective effect . However, the impact of raspberry fruit’s high antioxidant capacity might be limited by very low uptake into the bloodstream from dietary intake . Nonetheless, they could have beneficial effects on the gastrointestinal tract as they pass along the digestive system, dutch buckets system thus preventing oxidation from foods already in the stomach and GIT or by affecting food digestion, glucose levels, and calorie usage . In addition, raspberry contains a significant amount of ellagitannins; a large group of polyphenols that are beneficial to fight cervical cancer, cardiovascular disease, and diabetics .Raspberries have a short shelf life of 2 to 5 days because of their natural soft texture and sensitivity to mold and other pathogens. Postharvest handling and storage conditions, including packaging, relative humidity, temperature, and light, can affect the bioactive compounds in brambles . Cooling is by far the best technology for increasing the shelf-life of horticultural produce. Low temperatures slow pathogen growth and reduce the rate of deterioration of freshly harvested commodities, thus extending shelf life and the marketing period .

The recommended temperature for raspberry storage is 0-1℃ , but it is challenging to maintain this recommended temperature during transportation and marketing. Although low storage temperatures can slow the development of Botrytis cinerea infections, they do not provide adequate control when pathogen inoculum loadsare high . Acidity and SS as well as pigment compounds such as anthocyanins play an important role in berry marketability after storage , and the presence of light and temperature during storage might affect anthocyanin compound stability .Modification of storage or transport atmospheres help maintain raspberry shelf life and quality. Controlled atmospheres or modified atmospheres are created by reducing O2 and/or elevating CO2 concentrations and have the general effect of slowing senescence and extending shelf life . The fundamental difference between CA storage and MA packaging systems is that in the CA storage system, gas levels are rigidly maintained, whereas in the MAP system, the gas mixture is flushed into the package once, if at all, and concentrations vary over time with product respiration and package permeability . Active MAP is performed by removing some amount of air from the package and replacing it with the desired gas combination . High CO2 concentrations have a general inhibitory effect on microorganism growth and development. CA composed of high CO2 and low O2 was found to be fungistatic in controlling Botrytis alli, Rhizopus nigricans, and Penicillium expansum . Nine red raspberry genotypes were tested in CA storage at 1℃ and decay was strongly suppressed across all the genotypes . Raspberries exposed to CO2 levels of 20% or higher exhibited delayed gray mold decay and extended shelf life . High CO2 concentration also slows further ripening and softening in berries. Applying CA, even for a short time of 0.5 to 3 days, increased strawberry shelf life by 3 days, as well as reduced the endogenous ethylene production and ultimately maintained lighterand brighter colored and firmer fruit . In addition, lowering the O2 concentration in the storage atmosphere can be beneficial in extending the shelf life of fresh produce . In mangoes, respiration rate decreased about 20-25% in low O2 atmosphere compared to air . Storing fruit with higher CO2 atmospheres; however, can result in off-flavor development, perhaps due to the initiation of anaerobic respiration and production of fermentative volatiles. Also, oxygen levels less than 2 kPa may cause fermentation of raspberry fruit . MA packaged strawberries developed off-flavor which the authors suggested might be linked to a specific cultivar’s susceptibility to accumulate ethyl acetate . The raspberry cultivar, Qualicum, produced more ethyl acetate in modified atmosphere packaging compared to “Meeker” and “Chilliwack” .Raspberry is a high value fruit but their shelf life is impacted by high perishability. In 2020, the United States produced 111,000 tons of raspberries, at a value of US$469 million and California alone contributed fresh raspberries worth of US$395 million . Raspberry’s delicate morphology coupled with high respiration and transpiration rates make them vulnerable to rapid deterioration after harvest. The typical shelf life of raspberries ranges from 3 to five days . Decay, leakiness, loss of firmness, darkening of the red color, and off-flavors are common limiting factors contributing to short storage life of raspberries . It is well established that cooling is by far the best technology for increasing the shelf-life of horticultural produce. Low temperatures slow pathogen growth and reduce the rate of deterioration of freshly harvested commodities, thus extending shelf life and the marketing period . The recommended temperature for raspberry storage is 0-1℃ , but it is challenging to maintain this recommended temperature during transportation and marketing. Although low storage temperatures can slow the development of Botrytis cinerea infections, they don’t provide adequate control when pathogen inoculum loads are high .