Cryogenic Milling of Pistachio Shells for Animal Feed
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Solution Overview
Problem
Pistachio shells, which constitute half the weight of the fruit, are too hard for animals to digest and thus end up as solid waste, with limited utilization, while existing processing methods do not effectively address the challenge of converting them into a usable form.
Innovation Solution
The method involves grinding pistachio shells in a cooled, cryogenic milling system to achieve a specific particle size range (10 μm to 600 μm), reducing allergen content, increasing digestibility, and enhancing polyphenol release, using a cryo-compression milling system with parameters like grinding temperature and time to alter the shell's physical structure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If pistachio shells are ground using conventional milling methods, then the shells can be processed, but the equipment clogs and processing efficiency is low due to the hardness of the shells
Solution Approach 1:
The patent applies parameter changes by cooling the pistachio shells to cryogenic temperatures (e.g., using liquid nitrogen) before grinding. This temperature change transforms the physical properties of the shells, making them more brittle and easier to grind without clogging equipment, thereby improving both productivity and reliability
Solution Approach 2:
The patent utilizes phase transitions by transitioning the pistachio shells from ambient temperature to cryogenic temperature states. This phase change alters the mechanical properties of the shells, enabling efficient grinding while preventing equipment clogging
2Ease of manufacture
If pistachio shells are not processed, then they remain as solid waste, but processing them requires overcoming their extreme hardness (3.5 on Mohs scale)
Solution Approach 1:
The patent changes the temperature parameter to cryogenic levels, which fundamentally alters the mechanical strength and brittleness of the pistachio shells. This makes the extremely hard shells easier to process by conventional grinding methods
Solution Approach 2:
The patent applies preliminary action by pre-cooling the pistachio shells to cryogenic temperatures before the grinding operation. This preliminary treatment prepares the shells for easier processing by reducing their hardness and increasing brittleness
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This process converts pistachio shells into a form that is highly digestible and rich in polyphenols, suitable for animal nutrition products, reducing waste and improving production efficiency by minimizing clogging in milling equipment.
Implementation Method 1
grinding raw pistachio shells in a cooled, e.g., cryogenic, milling system
Implementation Method 2
a cooled compression milling system, e.g., a cryo-compression milling system
Data Source
AI summary
The present disclosure provides methods for processing pistachio shells based on cooled, e.g., cryogenic, grinding. In embodiments, such a method comprises grinding raw pistachio shells in a cooled compression milling system, e.g., a cryo-compression milling system, under conditions to provide ground pistachio shells having a D50 particle size in a range of from 10 μm to 600 μm. Animal nutrition products are also provided. In embodiments, an animal nutrition product configured to be ingested by an animal is provided, the animal nutrition product comprising ground pistachio shells having a D50 particle size in a range of from 10 μm to 600 μm.