Recipient Organization
CORNELL UNIVERSITY
(N/A)
ITHACA,NY 14853
Performing Department
Food Science
Non Technical Summary
Significant amounts of fresh produce are lost every year. Of particular concern are products that may be aesthetically imperfect but are otherwise fine, and byproducts that result from primary processing of fresh produce. We will use a new technology, Vacuum Microwave Drying to convert such products and byproducts relevant to NY State into novel foods of high nutritional and sensory quality. This work will directly contribute to a NY food industry that is diverse, sustainable, and profitable, and that produces a safe and healthy food supply. By utilizing resources that otherwise would be lost or underutilized, this work will also lead to improved use of the state's available agricultural resources. As a result of this project, we expect to generate at least one published paper and two conference talks in which the results of our research will be presented. One graduate student will be trained with financial help from this project, and this person will then be able to make contributions to the improvement of the US agriculture and Food sector when working in industry, government or academia. We will also communicate the results of the work directly to the internal and external stakeholders - directly or with help from our extension colleagues. Ultimately, we hope to see a practical implementation of the developed process and products, which most likely will take place after the completion of the project.
Animal Health Component
50%
Research Effort Categories
Basic
20%
Applied
50%
Developmental
30%
Goals / Objectives
We will use Vacuum Microwave Drying technology for the upcycling of physically imperfect fruit and vegetables, as well as select byproducts from fruit and vegetable processing, which will be converted into final products of high nutritional and sensory quality.Objective 1 (year 1): Identify optimal processing conditions (vacuum and microwave energy level, product temperature, drying time) for the Vacuum Microwave Drying of whole fruits (apples, grapes, peaches, berries) and vegetables (beets, broccoli).Objective 2 (year 2): Identify optimal product parameters (product concentration, aeration level, carrier gas for foaming), and processing conditions (vacuum and microwave energy level, product temperature, drying time) for the Vacuum Microwave Drying of foams prepared from fruit and vegetable purees, pastes and juices.Objective 3 (year 3): Using the optimal conditions identified, prepare a range snacks by VMD of both individual or mixed fruits and vegetables, and evaluate their quality (sensory, physico-chemical, microbiological) and storage behavior.
Project Methods
In Year 1, we will evaluate the use of VMD for the dehydration of whole fruit and fruit slices. Selected fruit: apples, grapes, peaches, and berries; selected vegetables: beets, broccoli. We will conduct drying runs at different initial product temperatures, vacuum and microwave power levels and drying times. To assess the effect of VMD, we will evaluate the quality (appearance, color, water activity, moisture content, texture) or the dried products. All processing and analytical testing will be conducted in triplicate, and the data analyzed statistically.In Year 2, we will identify the optimal product parameters (product concentration, aeration level, carrier gas for foaming), and processing conditions (vacuum and microwave energy level, product temperature, drying time) for the VMD of foams prepared from fruit and vegetable purees, pastes and juices. A special emphasis will be placed on evaluating the effect of the method used for creating the fam (agitation, injection), the choice of foaming gas (air, nitrogen, CO2 gas) on the foam structure and ultimately their impact on the final product structure. We will evaluate the quality (appearance, color, water activity, moisture content, structure, texture) or the dried products. All processing runs and analyses will be conducted in triplicate and data analyzed statistically.In Year 3, we will use the optimal conditions identified as art of Obj. 1 and 2 to prepare a range snacks by VMD of both individual or mixed fruits and vegetables. Tentatively, we plan to use apples a base for most products with additions of the other fruits and vegetables to the apple base. We will then evaluate the product quality (sensory, physico-chemical, microbiological) and storage behavior.Materials. Locally sourced fruits and vegetables will be prepared and processed in the Geneva Pilot Plant facility.Vacuum Microwave Drying (VMD) will be conducted using a 10 kW Medium-Scale REV unit (Enwave Corp.) in the Pilot Pkant in Geneva, NY. Characteristics: microwave power: 10kW; frequency: 2450 MHz; vacuum: 25-300 Torr.Air drying and freeze drying: For comparison purposes, the products will also be dried using conventional drying methods, using equipment available in the Food Processing Pilot Pant.Physical properties: The concentration of the liquid feeds and feed temperature will be measured using a Digital Refractometer, and reported in ºBrix.The total solids content will be measured using standard air drying.Water activity will be determined with an AquaLab Dew Point Water Activity Meter 4TE.The Lab color parameters will be determined using a Konica Minolta CR-400 Chroma Meter. Color will be recorded using the CIE-L* a* b* uniform color space.The structure of the final products will be evaluated using Scanning electron microscopy.Microbiological quality (total plate counts, thermophilic and mesophilic spore counts) will be determined using standard methodology.Aeration/foaming of purees and pastes (for Obj 2.). Depending on the product, it is anticipated that we will be able to incorporate air by high energy mixing, using high shear mixers. This is a simple and practical method, but will not allow controlled gas incorporation and foaming. To achieve this, we propose to use a carbonation stone assembly, which is routinely use for beverage carbonation in our Pilot Plant in Geneva. The carbonation (diffusion) stone consists of a piece of perforated stainless steel, with numerous pores of 0.5 - 2 micron in diameter. The stone will be submerged in the puree / paste, which will allow the gas bubbles to diffuse into the product and create a foam. The assembly can be used with air, CO2 gas or N2 gas, and by mounting it to gas tanks it will be possible to control the gas pressure and flow rate, and thus the level of foaming.To ensure that the foamy structure is maintained, the VMD conditions (microwave power and vacuum level) will be carefully controlled. We will start with a higher microwave power level and low vacuum to initiate drying and maintain the structure, and then will increase the vacuum to allow fast drying without increasing the temperature of the product too much. For example, we have achieved some preliminary success in obtaining cheese puffs using the following VMD drying stages: 1) 1.5 W/g for 600 s at 45-50 Torr (to allow fast initial drying to a moisture content of about 75-80%); 2) 2 W/g for 180 s at 15-20 Torr (increased energy input at lower pressure to 'puff' the cheese); 3) 1W/g for 600 s at 15-20 Torr, followed by 4) 0.5 W/g for 300 s at 10-15 Torr (reduced energy input and low pressure to keep the product temperature low and remove the remaining moisture). The specific VMD drying regime will be adapted to each product.