CAPSTONE PROJECT
Green Kitchen
Reducing food waste at the consumer level
MY ROLE
Sole UX/UI Designer
TOOLS
Figma, Photoshop, Stark
TIMELINE
Aug 2024 - April 2025
Challenge
Americans struggle to determine if their food is safe to eat, resulting in approx. 50% of all food in the U.S. being wasted at home. This contributes to hunger, food insecurity, wastes valuable resources, and harms the environment.
Solution
Designed a mobile app that tracks food inventory and freshness by linking grocery accounts and smart devices, offers quick food safety info and label explanations through scanning and resources, and suggests recipes to reduce food waste.
Results
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Addressed key pain points by simplifying food management and safety information access.
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Users completed all key tasks successfully, indicating high usability.
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Overall positive user feedback and experience, with clear potential to reduce food waste at home.
Research
Getting to know my users
As I explored the issue of household food waste, it was important to understand not only the scale of the problem, but also the everyday behaviors/what they currently do to determine if their food is still safe to eat, and the challenges people face when deciding if their food is still safe to eat.
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While food waste affects many households, I focused on individuals who have who have refrigerators and manage groceries, storage, and daily meals, those with similar lifestyle and background as my own. This convenience sampling approach was a limitation, but necessary due to time and resource constraints.
User Interviews and Insights
Participants used several informal methods to keep track of food freshness. Some verbally reminded household members to eat items before spoilage, which worked only when remembered. Others relied on making food visible by using glass containers or organizing items toward the front of the fridge. Some tried keeping inventory lists or meal planning, with meal planning seen as the most effective method. In the end, it was clear they lacked a reliable system.​​
Key Tasks
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People want to quickly get answers on what food they have in stock and how long it can stay in the fridge and cupboards.
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People want to quickly get answers about unfamiliar foods (or new foods).
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People want to quickly get answers about food terms, date labels, and the roles of the government and manufacturers.
“The oat milk. Like, ‘Oh, there's a weird thick sludge, and it's not expired yet. Is that fine?’”
“I'll go to the store and think, I need garlic powder, but I have no clue if I have some at home, and then I end up with three things of garlic powder.”
"...If it's not pasteurized....it makes me want to go look. I don’t know what the rules on that here are either."
Design
Sketches
Concept Testing
I concept tested early in the design process to validate potential design solutions with users, making sure the ideas aligned with their needs while reducing the risk of building the wrong solution. This helped guide key design concept decisions moving forward.
​Participants and Environment
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​3 College graduate students, 1 Researcher, 1 Engineer
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3 lived by themselves, 2 lived with other people
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3 on campus, 1 at their home, and 1 remotely over Microsoft Teams
Method
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Moderated concept walkthrough, using scenarios when needed
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Semi-structured interviews
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Used low-fidelity wireframes
Concept 1
Addressing how long their food is good for in the fridge and pantry using an inventory system.
1a. Linking Grocery Accounts​
- Design Tradeoffs: Affordability and accessibility vs Accuracy
1b. Linking Smart Devices​
​- Design Tradeoffs: Efficiency and Convenience vs Affordability and Accessibility
Concept 2
Exploring how users will get information about unfamiliar foods (or new foods).
2a. Scan unfamiliar food
- Design Tradeoffs: Efficiency vs Unreliable
2b. Manually search unfamiliar foods
- Design Tradeoffs: Intuitive/Familiar vs Inconvenient and Time-Consuming
Concept 3
Exploring how users will get information on date labels.
3a. Scan date labels
- Design Tradeoffs: Convenience vs Unreliable
3b. Uses voice assistant
- Design Tradeoffs: Efficiency vs Unreliable (not recognizing voice)
Concept Testing Feedback
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Some liked linking grocery accounts concept, others liked linking smart devices.
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Notifications for food about to go off, especially liked recipe suggestion.
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Would rather scan with the app to get information on the meaning of date labels vs manually search, or information on a food item.
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A way to edit where the food is located.
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Main concern - privacy, for linking smart devices option.
Scenario - Amelia's Smart Fix for Food Waste
Amelia lives alone, works late, and loves to cook, but her food often goes bad before she can use it. One night, unsure if her cheese is still good, she orders takeout again. A friend recommends Green Kitchen, an app that tracks food freshness. Excited, Amelia sets up smart cameras and scales, and finally stops guessing what’s safe to eat.
1. Amelia signs up for the Green Kitchen app.
2. The app takes Amelia to the Home Page, and she selects 'Add device'.
3. Amelia adds 'Cameras' and 'Scales' and receives confirmation.
4. Amelia taps home and selects 'Link account'.
5. She links Walmart, Target, and Whole Foods grocery accounts to the app and receives confirmation.
6. Amelia navigates to home and taps on 'Milk', and it takes her to the food details screen.
7. She selects 'Live View' to view what's in her fridge and cupboards in real time.
Prototype
Functional Requirements
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The system shall ... allow the user to add their food inventory to the app by connecting to smart devices.
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The system shall ... allow the user to add their food inventory to the app by linking their grocery store accounts with the app.
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The system shall ... be able to track and display how many days a food item has left until it goes bad.
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The system shall ... display an overview of details for each food item.
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The system shall ... provide information on resources on regulatory food guidelines.
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The system shall ... be able to scan food items to provide more information to the user.
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The system shall ... provide the ability to view the fridge and cupboards in real time.
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The system shall ... suggest recipes to the user based on the current inventory.
More on Features
On the home screen, foods about to expire are shown with a dot for days left. Clicking on an item gives details like shelf life, purchase and open dates, amount left, and signs of spoilage, helping users act quickly. For date labels and food terms, users can scan or check the resources screen for info about government and manufacturer roles.
Constraints and Challenges
Time was a constraint as I was a full time graduate student with one week to complete high-fidelity designs and prototyping, I focused on balancing effort and efficiency, making sure the most important screens for functionality were prioritized while still giving all screens the attention they needed. In the future, I’ll take it a step further by creating an outline for prioritizing screens early on and setting time blocks. It’s a small shift that’ll make my process even more streamlined while maintaining the quality and efficiency I already bring to my work and time management.
Prototyping in Figma
Evaluation
Usability Testing
I ran five in-person usability tests. Three women, two men, ranging from their 20s to their 70s, joined me in kitchens, on campus, and at a park. Some were new to the app, others had been part of my early interviews, getting a mix of fresh and familiar. I asked them to think out loud as they moved through tasks. I watched their hands hover, hesitate, and sometimes miss the mark. Every pause told me something design couldn’t.
Tasks included linking grocery accounts, adding smart devices, checking shelf life info, and finding food safety definitions. I gave scenarios where needed, for example: "Let’s say you are wondering what 'pasteurized' means, where would you go to find this information?"
​​Summary of Overarching Themes - Usability Testing
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"I wish I could start using this today."
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Task rate success was 100% for all tasks, meaning all users were able to complete the usability tasks. That sounds great, but it wasn't a perfect design and wasn't without its issues.​
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Time on task for locating shelf life information was slower for older users (40% of the group) than for younger users, and ALL users took longer to find this information.
More Details on the Challenges
I categorized usability issues from Minor to Severe, Cosmetic, and New Feature Requests to guide usability improvements.
1. Recipe suggestions were hard to find and limited in variety - minor, feature request​
✨ Revision: Added more recipes and a dedicated recipe screen.
Tradeoff: User explicitly suggested they select a recipe in the app, and it takes them to their favorite website. A future feature - to integrate APIs for personalized recipe filtering by ingredient, author, or website to maintain an efficient in-app experience.​
2. Difficulty finding shelf-life information, took longer to complete. - minor
✨ Revision: Improved layout and hierarchy and also adjusted font weight to improve visibility and usability.
Why? I consider cognitive load in my designs and chose not to add another screen even though two of my users tapped on the shelf life text indicating to me that they expected to be taken to another screen. Instead, I focused on improving the heirarchy on this screen to see if that would make for a better experience. I also made this choice knowing that users were still able to complete this task, just with slightly longer time on task.
Tradeoff: Opted for clarity, simplicity, mental effort vs meeting users' subconscious expectations.
3. Wanted time indicators on each screen - minor, feature request​
✨ Revision: Added time indicators to other screens, for example, the Fruit Inventory screen​
4. Icons were difficult to tap, especially for older users - severe
✨ Revision: Added padding to enlarge touch targets for easier navigation.
Touch target too small, needs padding
5. Users struggled to select multiple stores and devices because of radio buttons and needed visual cues - severe
✨ Revision: Replaced radio buttons with checkboxes to enable smooth multi-selection.
Final Design
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Clean, geometric, sans-serif typeface
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Modern feel, highly legible, and versatile
Refined Designs
To improve the user experience, I used insights from my usability tests to inform and guide the redesign.
Home
Add or Link
Link grocery accounts
Refrigerated Inventory
Food details
Live view
Scan
Resources
Connect smart devices
Fruit Inventory
Recipe suggestions
Recipe info
Prototype
Challenges I Faced and How I'd Do It Differently
During concept testing, I ran into a challenge where users often shifted the conversation toward potential features for the app, rather than focusing on the concepts I was presenting. If I were to do this differently in the future, I would use storyboards to better communicate the concepts and help keep the focus on the different ideas rather than specific features.
Impact
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Overall positive user feedback and experience.
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Users completed all key tasks successfully, indicating a high level of usability with the design.
“I like the whole idea around it because food waste is such a huge issue, so I think it will solve, you know, if it reduces even a little bit a food waste, then I think it’s a successful app.”
ISU Digital Repository
If you're up for reading 47 pages on my UX Design project, click on the link below to find it in the ISU Digital Repository! 😉