1 Reports on chilled foods, including issues of manufacture and distribution, are written by Ronan Gormley.
The 1970s and 1980s saw the rise in popularity of chilled foods, and the majority of the required research and development (R&D) was carried out in the COST 91-bis sub-group 3 (chilled foods) program (1985–1989).1-3 Prior to the COST 91-bis coordinated action, relatively little research and development (R&D) had been done on chilled foods, and the program’s outcomes continue to be the mainstay of the chilled foods market today.
2 Cold food’s nutritional value, safety, and quality
Because chilled meals are perceived by consumers as “nearer to fresh” than other processed foods, they have a higher perceived quality and are typically of good quality; in other words, consumer perception is usually accurate.3-5
As product varieties grow, refrigerated food shelf space in supermarkets keeps growing. However, because their products have limited shelf lives, manufacturers of chilled foods are effectively in a difficult spot. The difference in heat needed to defrost frozen beef (1 kg) from -5 to 0ºC (195kJ) versus warming from 0 to 5ºC (16kJ) serves as an example of this. Accordingly, it is 12 times easier to misuse the temperature of chilled beef than frozen beef. The “safety moat” surrounding the frozen beef “castle” is made of ice.5.
Therefore, temperature abuse can occur in minutes for chilled goods and hours for frozen foods if the product is exposed to warm (hostile) ambient temperatures during distribution and retailing, or on the drive home after shopping in a warm car trunk.
3 Obstacles in technology
“How many safety hurdles has the product got?” is a crucial question in product development.6. Considering how perishable chilled foods are, this is especially true. Modified atmosphere (MA) and chill (2–5ºC) are two safety requirements, for instance, for certain brands of bagged lettuce. Five components make up smoked salmon: vacuum-packed, salted, lowered water activity, smoked, and chilled (2–5ºC). The significantly extended shelf life of smoked salmon in comparison to bagged lettuce is indicative of this.
The common barrier for all chilled items, and in certain situations the sole one, is chill temperature (2–5ºC), underscoring the significance of an effective chill chain. Certain items, particularly fish and poultry, are best served extremely cold or crust frozen, which involves lowering the temperature to minus 1 or 2 degrees Celsius and causing a little amount of ice to develop. While most in-store chill cabinets are not set to this degree, super chilling can extend shelf life by two to three days.
4 Cold chain
Cold chains can vary in length based on the needs. A product that is made in a nearby facility and then delivered to a nearby food store is an example of a short chain. When a product is shipped by air to far-off markets, it goes through a lengthy chain that includes truck delivery to an airport, sometimes via one or two flights, truck distribution to a central depot, and finally truck delivery to grocery shops. Ultimately, it is delivered to the house by customers or a delivery service, where it is kept in the refrigerator.
A slow baton change indicates mild temperature abuse, and a baton drop indicates substantial temperature abuse. This makes a cold chain analogous to a relay race. Each person in the chill chain needs to be extremely skilled and understand the need of maintaining precise temperature control at each stage of the trip. The following are risk points in the chain where abuse could happen:
putting unchilled food in a refrigerated truck and thinking the unit will keep it cold; truck refrigeration units aren’t meant for chilling food; they’re meant to keep pre-chilled food cold.
the supermarket’s rear entrance, where delivered pallets of chilled products are kept until they are needed in a holding chilled store
5 Chilling in the freezer
Freeze chilling, as the name implies, is a twofold technology in which a product is first frozen at -30ºC and then thawed to 2–5ºC before being loaded into a retail display cabinet. This allows the consumer to view the product as chilled and believes it to be quite fresh.5,11
Foods must, first and foremost, be suitable for freezing and thawing. This means that they must not suffer considerable structural damage from ice crystal formation and should drip very little or not at all during the thawing process. This criterion rules out leafy greens and salads, as well as a number of other foods with delicate cell structures and some fruits like tomatoes and strawberries. This does not take away from the abundance of items that can be frozen, including most fish and meats, a variety of other fruits and vegetables, a large range of ingredients, and prepared foods like ready meals.5.
It is essential to carefully regulate the tempering/thawing process. You can rent specialized equipment that uses hot and cold air pulses to temper up to 3,000 frozen meals to a temperature of 2 to 5 degrees Celsius over night. Before being placed in a display cabinet, prepacks, such as MA-packed salmon portions, can be let to settle over night in a retailer’s chill room.
At the end of the thawing/tempering cycle, consumer packs must have a use-by date. The consignee, or retail level, is where this can be handled. Nonetheless, the consignor is required to include shelf life instructions with the cargo. Depending on the product, these instructions may include a two-, four-, or six-day shelf life after thawing or chilling.
Some food products, like fish, must have the term “defrosted” attached to their product name.7. The following are possible benefits and drawbacks of freeze-chilling:12