Page 185 - 《水产学报》2025年第5期

康宁哲，等 水产学报, 2025, 49(5): 059815

Fish sarcoplasmic protein replaces chicken protein to
make a naturally enticing and digestible cat food

1,2
3
1,2
KANG Ningzhe , LONG Siyu , HE Yiyuan , HUANG Qilin 1,2*
1. College of Food Science and Technology, Huazhong Agricultural University, Wuhan 430070, China;
2. National R & D Branch Center for Conventional Freshwater Fish Processing (Wuhan), Wuhan 430070, China;
3. Wuhan Optical Valley No.2 Senior High School, Wuhan 430070, China

Abstract: For global net-zero targets, recycling of sarcoplasmic proteins from the surimi processing industry, which are typic-
ally considered biomass waste, can promote green and low-carbon processing of surimi and achieve energy conservation and
emission reduction. This study investigates the effects of replacing chicken protein with silver carp (Hypophthalmichthys
molitrix) sarcoplasmic protein in cat food on the feeding behavior and evaluates its digestibility. In this research, H. molitrix
sarcoplasmic proteins were recovered using pH-shifting and chitosan-flocculation methods analyzed for amino acid composi-
tion and flavor. These proteins were then used as a substitute for chicken breast, combined with butter and other excipients to
formulate cat food. Single-factor experiments were conducted using baking time, baking temperature, potato starch addition, H.
molitrix sarcoplasmic protein addition, and butter addition to score the finished products. Response surface methodology was
employed to determine the optimal process conditions for cat food production. Finally, the basic nutritional composition, palat-
ability, and pepsin digestibility of the sarcoplasmic protein-enriched cat food were compared with two commercially available
extruded puffed and low-temperature baked cat foods that have high sales volumes and positive ratings. The results showed the
optimal process conditions for 100 g of cat food were as follows: H. molitrix sarcoplasmic protein addition of 22.85 g, baking
temperature of 80 °C, baking time of 8.07 h, butter addition of 9.22 g. H. molitrix sarcoplasmic proteins were found to be rich in
amino acids, particularly lysine (7.21 g/100 g). They also contained high levels of flavour-enhancing amino acids, such as
glutamic acid (9.59 g/100 g) and aspartic acid (9.22 g/100 g), with taste activity values of 959.00 and 307.33, respectively.
Additionally, high odour activity values of nonanal (24 640) and octanal (1 514), which impart a fishy flavour, significantly
contributed to the overall flavour of the cat food, making it highly attractive to cats and serving as a natural food attractant. The
study demonstrated that H. molitrix sarcoplasmic protein can effectively replace chicken protein. Moreover, the digestibility of
cat food enriched with sarcoplasmic protein 94.07%, which was higher than that of the two commercial cat foods tested. This
ingredient that H. molitrix sarcoplasmic protein is an ideal protein ingredient for replacing chicken in cat food preparation. This
research provides a valuable reference for the application of H. molitrix sarcoplasmic proteins in pet food.

Key words: Hypophthalmichthys molitrix; sarcoplasmic protein; response surface methodology; cat food; attract food; sensory
evaluation

Corresponding author: HUANG Qilin. E-mail: hql@mail.hzau.edu.cn
Funding projects: China Agriculture Research System of MOF and MARA (CARS-45-28)

https://www.china-fishery.cn 中国水产学会主办 sponsored by China Society of Fisheries
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