Discover how unavoidable food waste in manufacturing can be transformed into sustainable opportunities with innovative by-product utilization and life cycle assessments.
The food system is a major contributor to environmental impacts, generating significant greenhouse gas (GHG) emissions and consuming vast amounts of land, water, and energy. Every step in food production—from farming to processing, packaging, and distribution—demands resources. Yet, when food is wasted along the supply chain, all these upstream efforts are lost.
When we talk about food loss and waste, the conversation often focuses on retail and consumer waste—expired groceries, unsold produce, or leftovers discarded at home. But a large share of waste happens before food even reaches the supermarket. Food manufacturing alone account for nearly 19% of total food waste in the EU. The majority of these materials are materials such as fruit peels, cereal bran, spent grains, dairy residues, and meat-processing by-products. These are called “unavoidable waste”.
Unavoidable waste in food manufacturing: A missed opportunity
Unlike avoidable waste, which results from overproduction, inefficiencies, or spoilage, unavoidable food manufacturing waste refers to by-products that naturally arise during food manufacturing. These include materials such as seeds, bones and spent grain.
Different food processing industries and their main by-products or wastes generated
Food industries | By-products or wastes generated |
|---|---|
Fruit and vegetable industry | Peelings, stems, seeds, shells, bran, trimmings, residues after extraction |
Grain processing industry | Husks, hull, bran |
Brewery and winery industry | Brewing process: spent grain, hot trub, residual yeast Grape growing and winemaking process: vine prunnings, grape stalks, grape pomace, grape seeds, yeast lees, tartrate, carbon dioxide, wastewater |
Marine industry | Viscera, heads, offal, backbones, blood, sheels |
Meat industry | Carcasses, hides, hoofs, feathers, manure, offal, viscera, bones, fat, meat trimmings, blood |
Dairy industry | Whey, curd, milk sludge |
Adapted from: Mateos-Aparicio, Inmaculada, and A. Matias. "Food industry processing by-products in foods." The role of alternative and innovative food ingredients and products in consumer wellness. Academic Press, 2019. 239-281.
While these materials cannot be prevented, they hold significant potential for reuse in food, feed, bioenergy, and bioproducts. For example, in orange juice production, large quantities of peels, seeds, and pulp are generated. If these materials are discarded, they are considered waste. However, when processed into essential oils, fiber-rich additives, or biofuel, they become co-products, sharing the environmental burden and reducing the carbon footprint of both products.
Yet, many food manufacturers still classify these materials as waste, incurring unnecessary disposal costs while missing sustainability and financial opportunities.
Recognizing the value of unavoidable waste is the first step toward a more circular and efficient food system.
In this article, we’ll explore:
Industry examples of smart by-product utilization
Traditionally, food manufacturing by-products have been managed through low-value disposal methods such as landfilling, incineration, or conventional composting. However, these approaches fail to capture the true potential of these nutrient-rich and functionally valuable materials. Instead of treating by-products as waste, the food industry is now shifting towards valorization strategies that extract bioactive compounds, functional ingredients, and industrial feedstocks, creating new economic opportunities while improving sustainability.
Many agro-food by-products contain significant nutritional value, along with techno-functional properties such as water-holding capacity, oil retention, gelling, and thickening abilities. These properties allow them to be transformed into high-value functional ingredients, rather than being discarded.
By-products can be repurposed into:
Functional and bioactive ingredients: peptides, proteins, polyphenols, prebiotics, vitamins, and essential fatty acids.
Natural food additives: antimicrobial, antioxidant, and natural color compounds.
Nutritional and functional enhancers: incorporated into bakery, dairy, beverages, and dietary supplements.
For instance, when 7.5% of pomegranate peel is added to biscuits, it enhances mineral content, allowing the product to be labeled as a “source of calcium” under EU regulations. Similarly, fruit and vegetable by-products can be integrated into functional foods to improve fiber content, antioxidant properties, and shelf stability.
Beyond food applications, by-products can serve as renewable feedstocks in biorefinery models, where they are converted into:
Bio-based chemicals for food and pharmaceutical industries.
Microbial oils and enzymes for industrial applications.
Biosurfactants and biopolymers for sustainable packaging solutions.
Natural colorants as eco-friendly alternatives to synthetic dyes.
The shift from waste disposal to by-product valorization represents a new frontier in food processing, turning previously discarded materials into high-value functional food ingredients and renewable industrial resources.
Explore Detailed By-Product Benefits & Use Cases
How LCA allocation methods shape sustainability perception
In food manufacturing, unavoidable waste is often described as by-products. But in Life Cycle Assessment (LCA), these materials are referred to as co-products. The way emissions are assigned to co-products can drastically alter their perceived environmental impact.
For manufacturers, getting this right matters. If unavoidable waste is misclassified or incorrectly allocated in an LCA, sustainability reports can misrepresent a company’s actual environmental performance—sometimes making them look worse than they really are.
How does the life cycle assessment allocate environmental impact for co-products?
The ISO 14044 Standard provides a step-by-step framework for handling co-products and ensuring that environmental impact is distributed fairly.
Step 1: Avoid allocation if possible
Before deciding how to split emissions between co-products, ISO 14044 recommends avoiding allocation altogether by:
Process Subdivision: Separating the production process into distinct steps so emissions can be directly traced to each co-product.
System Expansion: If a co-product replaces another product in the market, subtract its avoided emissions from the total footprint.
Example: Cheese and whey processing
When making cheese, whey is produced as a by-product.
If whey is discarded, the full environmental burden of dairy farming and processing is assigned to the cheese.
But if the whey is turned into protein supplements or animal feed, it reduces the need for soy protein, which would otherwise be grown using land, water, and energy.
By applying System Expansion, the avoided emissions from soy protein production are credited to the cheese and whey system, lowering their carbon footprint.
Step 2: Use physical allocation when necessary
If System Expansion is not possible, ISO 14044 recommends splitting emissions based on measurable physical properties such as mass, energy, or protein content. This method ensures that environmental impact is distributed in a way that reflects the composition of the final products.
Example: Processing milk into cream and skim milk
100 kg of milk is processed into 20 kg of cream and 80 kg of skim milk.
Since emissions cannot be directly traced, they are split proportionally by weight:
Cream gets 20% of the footprint.
Skim milk gets 80%.
Step 3: Economic allocation as a last resort
If System Expansion and Physical Allocation are not feasible, ISO 14044 allows for economic allocation, where emissions are distributed based on market value. However, this approach is considered the least preferred method because prices fluctuate over time, which can distort the environmental assessment of a product. If economic allocation is used, it is important to carefully interpret sustainability claims, as market-driven distortions can misrepresent the environmental impact of a product.
Example: Processing milk into cream and skim milk
100 kg of milk is processed into 20 kg of cream and 80 kg of skim milk. If cream accounts for 60% of the total revenue and skim milk 40%, then:
Cream gets 60% of the footprint.
Skim milk gets 40%. of the footprint
Understanding how emissions are allocated in Life Cycle Assessments is critical for food manufacturers looking to make accurate sustainability claims. A misclassified by-product can unfairly inflate a product’s footprint, while an overlooked co-product can understate environmental benefits. By applying the right allocation methods, companies can ensure that their sustainability efforts are properly reflected, avoid misleading impact assessments, and unlock new opportunities for waste reduction and resource efficiency.
Navigating LCA allocation can be complex. If you need personalized support or expert guidance on maximizing your by-product value, contact our team for tailored assistance.
What can food manufacturers do to avoid food waste?
For food manufacturers, unavoidable waste presents an opportunity to improve sustainability and profitability. Instead of discarding valuable by-products, companies should take a strategic approach to identifying, measuring, and repurposing these materials.
1. Identify which by-products can be repurposed
The first step is to assess waste streams and determine which by-products have potential for reuse. Many food manufacturers already generate materials that can be repurposed in food, feed, bioenergy, or bioproducts, but they are often classified as waste due to lack of awareness or processing infrastructure. Conducting waste audits can help companies identify where these opportunities exist.
2. Use tools to measure the emissions and costs of repurposing
Once potential by-products have been identified, food manufacturers need to quantify the environmental and financial impact of repurposing versus disposal. Life Cycle Assessment (LCA) tools can compare the emissions, costs, and resource use associated with different strategies—whether it’s turning spent grains into animal feed, processing whey into protein, or extracting compounds from fruit peels. These tools help determine the most sustainable and cost-effective approach while ensuring compliance with LCA allocation guidelines.
Transform your sustainability strategy with Nature Preserve’s dynamic LCA platform—designed to simplify your environmental impact assessments and optimize production efficiency. Sign up for a free trial today and see how our tools can work for you.
The future of unavoidable waste in food manufacturing
With the right strategies in place, food manufacturers can turn unavoidable waste into high-value resources, contributing to a more sustainable and profitable food system. By repurposing by-products, companies can reduce disposal costs, lower their carbon footprint, and create new revenue streams, all while aligning with evolving sustainability regulations and consumer expectations.
Looking Ahead: what about agricultural waste?
While food manufacturers are rethinking their by-products, there's another stage of unavoidable food waste happening even earlier—on the farm. From crop residues to processing leftovers before raw materials even reach factories, agricultural waste represents a critical piece in the sustainability conversation.
In Part 2 of this series, we’ll explore how unavoidable agricultural waste can be better managed for sustainability and profitability—closing the loop on food system waste. Subscribe to our newsletter to be the first to read the article.
Sign up now and never miss an update.