Food processing by-products are increasingly being recognised as valuable sources of functional ingredients rather than simply waste streams. A recent review published in Foods examines how advances in extraction technologies, fermentation and integrated biorefinery systems are enabling the recovery of ingredients for food, feed and other industrial applications. Among the opportunities highlighted are several that are directly relevant to bakery manufacturers.

For industrial bakers, the greatest interest lies in the recovery of ingredients that can improve nutritional value, support clean-label formulations and contribute to more efficient use of food resources.

Valuable ingredients from familiar by-products

The review identifies a wide range of food processing side streams that contain compounds suitable for recovery, including fruit pomace, cereal bran, brewer's spent grain, citrus peel, whey and vegetable residues. These materials contain dietary fibre, proteins, polyphenols, minerals and other bioactive compounds that can be incorporated into value-added food ingredients.

Previous Baking Europe features have explored the potential of ingredients such as apple pomace and brewer's spent grain(pg 28 BE Summer 25). The review places these examples within the wider context of food waste valorisation, highlighting the growing interest in recovering functional ingredients from agricultural and food-processing by-products.

Among the most commercially attractive applications are dietary fibres recovered from fruit pomace, cereal bran and vegetable residues, together with protein concentrates and bioactive peptides derived from dairy and cereal processing. According to the authors, these ingredients are increasingly being incorporated into food formulations to improve nutritional quality while supporting more sustainable production systems.

Supporting clean-label development

Food processing by-products also provide opportunities to replace conventional additives with naturally derived ingredients.

The review highlights pectin recovered from citrus peel and apple pomace, which is widely used as a gelling, stabilising and thickening ingredient. It also identifies natural pigments recovered from grape pomace and tomato by-products, together with essential oils from citrus residues that exhibit antimicrobial and antioxidant properties and have been proposed as natural preservatives for food applications.

As manufacturers continue to respond to consumer demand for clean-label products, these naturally derived ingredients are attracting increasing attention.

Recovery technologies continue to develop

The review describes a range of technologies used to recover valuable compounds from food by-products. These include ultrasound-assisted extraction, microwave-assisted extraction, pressurised liquid extraction and supercritical carbon dioxide extraction, all of which aim to improve extraction efficiency while reducing solvent use and processing times compared with conventional methods.

The authors also assess these technologies according to their Technology Readiness Level (TRL). Anaerobic digestion and conventional fermentation are identified as fully commercial technologies, while ultrasound-assisted extraction, microwave-assisted extraction and supercritical fluid extraction have progressed to pilot-scale and industrial applications. Other technologies, including digital biorefineries and artificial intelligence-assisted process optimisation, remain at earlier stages of development.

For bakery manufacturers, the review suggests that the most immediate opportunities are likely to come from ingredients produced using technologies that have already demonstrated commercial potential.

Commercial products already on the market

The review also highlights several examples of commercially available upcycled ingredients.

These include okara flour produced from the fibre-rich pulp remaining after soymilk production, together with ingredients derived from brewer's spent grain, oat protein, pineapple fibre and green banana flour. According to the review, these ingredients are already being incorporated into cookies, crackers, baking mixes, snack products and other bakery applications.

Such examples illustrate that ingredient recovery from food-processing side streams is no longer confined to research projects but has begun to establish a commercial presence within the food industry.

A circular approach to ingredient development

The review concludes that food waste should increasingly be regarded as a secondary raw material capable of generating environmental, economic and nutritional value. Integrated biorefinery systems seek to recover high-value compounds first before converting the remaining biomass into energy or other products, maximising the value obtained from each raw material.

The review points towards continued development of ingredients recovered from existing food-processing streams. As interest in sustainability, resource efficiency and clean-label formulation continues to grow, upcycled ingredients are likely to remain an area of active innovation for both ingredient suppliers and bakery manufacturers.