On-site Planning
Installation & Commissioning
Automated & Energy Efficient
Client Name: Gilroy Foods & Flavors – Snack Foods Division
Country: United States of America
Region: Gilroy, California – the Garlic Capital of the World, a core onion growing area in California's Central Valley
Core Products: Classic crispy onion rings, spicy corn chip flavor onion rings, ranch dressing flavor onion crisps, onion powder snack crisps
Equipment Configuration: Hadof custom fully automatic onion peeling and slicing + dual?zone oil bath frying line (capacity 600kg/h, including automatic coating and seasoning, and nitrogen packaging integration)
Commissioning Date: Q1 2025
The United States is one of the world's largest consumers of onions. Gilroy, California, is not only the Garlic Capital of the World but also a hub for onion processing. Gilroy Foods, a subsidiary of Conagra Brands, processes tens of thousands of tons of onions annually, supplying restaurant chains and the food industry across the country. With the snack market for fried onion rings growing at 15% annually, Gilroy decided to launch retail?packaged fried onion rings and enter supermarket channels. However, during industrial production, they encountered challenges that traditional processes could not overcome:
Onion rings easily fall apart, difficult to shape: Onion rings are sliced from natural onions. After coating, they easily break apart during frying, with an integrity rate below 60%, failing to meet retail packaging requirements.
Uneven coating thickness: Traditional coating methods result in inconsistent powder thickness – too thick in some areas makes them hard, too thin in others exposes the onion, leading to high oil absorption and unstable quality.
Residual pungency: American consumers prefer a mild taste, but traditional frying cannot fully remove the sharp, pungent flavor of onions, affecting repeat purchases.
Variability among onion varieties: Yellow, white, and red onions differ significantly in moisture content, pungency, and sugar content, making a fixed?parameter process unsuitable.
Gilroy Foods' technical team had evaluated equipment from several German and Dutch manufacturers, but found that European machines were designed mainly for potatoes and could not solve the onion ring shaping problem. Through the American Onion Association, they initiated joint R&D with Hadof. After nine months, we developed this industrial onion frying line specifically designed for "California's diverse onion varieties + American flavors."
1. Laser Diameter Measurement + AI Adaptive Slicing – Uniform Onion Rings, Integrity Rate 92%
To solve the shaping problem, we integrated a laser diameter measurement system at the slicing stage to scan onion size in real time. The AI algorithm automatically adjusts slice thickness and cutting path to ensure uniform ring diameter. After slicing, flexible ring holders keep the rings in shape before coating, completely preventing breakage. The finished product integrity rate jumped from 60% to 92%, meeting retail packaging standards.
2. Dual?Layer Coating + Airflow Conveyed Breading – Coating Uniformity ±0.3mm
We designed a dual?layer coating process: a first layer of liquid batter fills surface irregularities and provides adhesion; a second layer of dry powder is evenly distributed by airflow conduction. Coating thickness tolerance is controlled within ±0.3mm, creating a perfect crispy crust after frying and reducing oil absorption by 25%.
3. Ultrasonic De?pungency Pre?treatment – 95% Pungency Removal, Mild Taste
To address the pungency issue, we added an ultrasonic?assisted de?pungency system: onion rings are soaked in a mild alkaline solution under 40kHz ultrasonic waves, accelerating the extraction of pungent compounds (thiosulfinates). After 15 minutes of treatment, pungent compounds are reduced by 95%, while the natural sweetness of the onion is retained, appealing to American tastes.
4. Near?Infrared Moisture Detection + Dual?Zone Frying – One?Click Adaptation for Yellow, White, and Red Onions
We integrated a near?infrared moisture meter at the fryer entrance to instantly detect moisture differences among yellow, white, and red onions. The AI algorithm automatically adjusts frying temperature and time: yellow onions (high moisture) – first zone 185°C/second zone 155°C; white onions (medium moisture) – 175°C/145°C; red onions (high sugar) – 170°C/140°C. Changeover time between varieties was reduced from 2 hours to 8 minutes, ensuring consistent color and texture across different onion types.
Capacity and Quality Leap
Daily capacity: Increased from 2.5 tons/day on the pilot line to 12 tons/day on the automated line (two shifts), capable of running continuously for 25 days without quality fluctuations. Total production in Q1 2025 exceeded 2,800 tons, with product qualification rate rising from 72% to 94%.
Channel Breakthrough
The high integrity rate, uniform coating, and mild taste helped Gilroy's "Crispy Onion Rings" series quickly enter 4,500 Walmart stores and 2,000 Kroger supermarkets across the US, and become retail partners with restaurant chains such as A****e‘s and C****’s. Exports to Canada grew by 300% year?on?year, establishing the brand as the top fried onion ring brand in North America.
Economic Benefits
Return on Investment: The production director at Gilroy Foods stated: "The traditional line required 24 people per shift; now the entire line runs with just four. We save over $2 million annually in labor costs alone. Combined with lower oil consumption and higher yield, the actual payback period is under 16 months."
Product Premium: The retail?ready intact onion rings and uniformly crispy texture allow Gilroy's fried onion rings to command a 50% higher retail price than similar foodservice products, achieving the highest profit margin in the snack division.
"Hadof's equipment turned our California onions from a restaurant side dish into a household snack. Now every onion ring carries the sunshine of Gilroy and perfect crispiness – exactly what American consumers want."
—— Michael Chen, Vice President of Operations, Gilroy Foods & Flavors
